Sticky fails to open after 7th June's update

I restarted after applying the 2021-06-07 update, and sticky fails to open.

$ sticky
Traceback (most recent call last):
  File "/usr/lib/sticky/sticky.py", line 605, in do_activate
    self.load_notes()
  File "/usr/lib/sticky/sticky.py", line 749, in load_notes
    self.generate_note(note_info)
  File "/usr/lib/sticky/sticky.py", line 734, in generate_note
    note = Note(self, self.dummy_window, info)
  File "/usr/lib/sticky/sticky.py", line 118, in __init__
    self.title_style_manager = XApp.StyleManager(widget=self.title_box)
  File "/usr/lib/python3.9/site-packages/gi/overrides/__init__.py", line 32, in __getattr__
    return getattr(self._introspection_module, name)
  File "/usr/lib/python3.9/site-packages/gi/module.py", line 123, in __getattr__
    raise AttributeError("%r object has no attribute %r" % (
AttributeError: 'gi.repository.XApp' object has no attribute 'StyleManager'

I installed sticky from the Manjaro’s official repositories, and it used to work before this update.
I am using Manjaro XFCE stable branch.

$ inxi -Fazi
System:    Kernel: 5.10.41-1-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0 
           parameters: BOOT_IMAGE=/boot/vmlinuz-5.10-x86_64 root=UUID=067bb185-2ee6-4461-8d00-69086fb7fed6 rw quiet 
           udev.log_priority=3 
           Desktop: Xfce 4.16.0 tk: Gtk 3.24.24 info: xfce4-panel, vala-panel wm: xfwm4 vt: 7 dm: LightDM 1.30.0 
           Distro: Manjaro Linux base: Arch Linux 
Machine:   Type: Laptop System: HP product: HP 250 G5 Notebook PC v: Type1ProductConfigId serial: <filter> Chassis: 
           type: 10 serial: <filter> 
           Mobo: HP model: 81EB v: 61.41 serial: <filter> UEFI: Insyde v: F.24 date: 01/05/2017 
Battery:   ID-1: BAT1 charge: 32.1 Wh (100.0%) condition: 32.1/32.1 Wh (100.0%) volts: 16.7 min: 14.6 
           model: Hewlett-Packard PABAS0241231 type: Li-ion serial: <filter> status: Full 
CPU:       Info: Dual Core model: Intel Core i3-6006U bits: 64 type: MT MCP arch: Skylake family: 6 model-id: 4E (78) 
           stepping: 3 microcode: E2 cache: L2: 3 MiB 
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 16006 
           Speed: 500 MHz min/max: 400/2000 MHz Core speeds (MHz): 1: 500 2: 500 3: 500 4: 500 
           Vulnerabilities: Type: itlb_multihit status: KVM: VMX disabled 
           Type: l1tf mitigation: PTE Inversion; VMX: conditional cache flushes, SMT vulnerable 
           Type: mds mitigation: Clear CPU buffers; SMT vulnerable 
           Type: meltdown mitigation: PTI 
           Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via prctl and seccomp 
           Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer sanitization 
           Type: spectre_v2 
           mitigation: Full generic retpoline, IBPB: conditional, IBRS_FW, STIBP: conditional, RSB filling 
           Type: srbds mitigation: Microcode 
           Type: tsx_async_abort status: Not affected 
Graphics:  Device-1: Intel Skylake GT2 [HD Graphics 520] vendor: Hewlett-Packard driver: i915 v: kernel bus-ID: 00:02.0 
           chip-ID: 8086:1916 class-ID: 0300 
           Device-2: Chicony HP TrueVision HD type: USB driver: uvcvideo bus-ID: 1-5:3 chip-ID: 04f2:b56c class-ID: 0e02 
           serial: <filter> 
           Display: x11 server: X.Org 1.20.11 driver: loaded: intel unloaded: modesetting alternate: fbdev,vesa 
           display-ID: :0.0 screens: 1 
           Screen-1: 0 s-res: 1600x900 s-dpi: 96 s-size: 423x238mm (16.7x9.4") s-diag: 485mm (19.1") 
           Monitor-1: eDP1 res: 1600x900 hz: 60 dpi: 120 size: 340x190mm (13.4x7.5") diag: 389mm (15.3") 
           OpenGL: renderer: Mesa Intel HD Graphics 520 (SKL GT2) v: 4.6 Mesa 21.1.2 direct render: Yes 
Audio:     Device-1: Intel Sunrise Point-LP HD Audio vendor: Hewlett-Packard driver: snd_hda_intel v: kernel 
           alternate: snd_soc_skl bus-ID: 00:1f.3 chip-ID: 8086:9d70 class-ID: 0403 
           Sound Server-1: ALSA v: k5.10.41-1-MANJARO running: yes 
           Sound Server-2: JACK v: 0.125.0 running: no 
           Sound Server-3: PulseAudio v: 14.2 running: yes 
Network:   Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet vendor: Hewlett-Packard driver: r8169 
           v: kernel port: 3000 bus-ID: 01:00.0 chip-ID: 10ec:8168 class-ID: 0200 
           IF: eno1 state: down mac: <filter> 
           Device-2: Intel Wireless 3165 driver: iwlwifi v: kernel port: 3000 bus-ID: 02:00.0 chip-ID: 8086:3165 
           class-ID: 0280 
           IF: wlo1 state: up mac: <filter> 
           IP v4: <filter> type: dynamic noprefixroute scope: global broadcast: <filter> 
           IP v6: <filter> type: noprefixroute scope: link 
           WAN IP: <filter> 
Bluetooth: Device-1: Intel Bluetooth wireless interface type: USB driver: btusb v: 0.8 bus-ID: 1-4:2 chip-ID: 8087:0a2a 
           class-ID: e001 
           Report: rfkill ID: hci0 rfk-id: 1 state: up address: see --recommends 
Drives:    Local Storage: total: 931.51 GiB used: 34.74 GiB (3.7%) 
           SMART Message: Required tool smartctl not installed. Check --recommends 
           ID-1: /dev/sda maj-min: 8:0 vendor: Toshiba model: MQ01ABD100 size: 931.51 GiB block-size: physical: 4096 B 
           logical: 512 B speed: 6.0 Gb/s rotation: 5400 rpm serial: <filter> rev: 4C scheme: GPT 
Partition: ID-1: / raw-size: 51.76 GiB size: 50.64 GiB (97.85%) used: 32.03 GiB (63.3%) fs: ext4 dev: /dev/sda5 
           maj-min: 8:5 
           ID-2: /boot/efi raw-size: 260 MiB size: 256 MiB (98.46%) used: 103.3 MiB (40.4%) fs: vfat dev: /dev/sda1 
           maj-min: 8:1 
           ID-3: /home raw-size: 22.98 GiB size: 22.45 GiB (97.70%) used: 2.61 GiB (11.6%) fs: ext4 dev: /dev/sda9 
           maj-min: 8:9 
Swap:      Kernel: swappiness: 60 (default) cache-pressure: 100 (default) 
           ID-1: swap-1 type: zram size: 2 GiB used: 1.2 MiB (0.1%) priority: 5 dev: /dev/zram0 
Sensors:   System Temperatures: cpu: 34.0 C mobo: 29.8 C 
           Fan Speeds (RPM): N/A 
Info:      Processes: 209 Uptime: 19m wakeups: 1 Memory: 3.73 GiB used: 2.68 GiB (71.8%) Init: systemd v: 247 
           tool: systemctl Compilers: gcc: 11.1.0 clang: 11.1.0 Packages: pacman: 1593 lib: 334 Shell: Bash v: 5.1.8 
           running-in: xfce4-terminal inxi: 3.3.04 

A temporary solution is to install xapps-git and sticky-git from the AUR.