FYI
I also had this problem but with another name.
I am on Manjaro Sway v1.7 (x86 NOT Arm).
sudo pamac update ✔
Preparing...
Synchronizing package databases...
Refreshing manjaro-sway.db...
Error: manjaro-sway.db: manjaro-sway: key "Jonas Strassel <info@jonas-strassel.de>" is disabled
invalid or corrupted database (PGP signature)
Failed to synchronize databases
I enabled info@jonas-strassel.de, refreshed mirrors and then ran the update again.
~ sudo pamac update ✔
Preparing...
Synchronizing package databases...
Warning: lib32-mesa: local (22.0.0-1) is newer than multilib (21.3.8-2)
Resolving dependencies...
Checking inter-conflicts...
To upgrade (2):
firefox 100.0-0.1 (99.0.1-1) extra 84.8 MB
manjaro-keyring 20220504-2 (20220503-1) core 112.4 kB
Total download size: 84.9 MB
Total installed size: 1.0 MB
Apply transaction ? [y/N] y
Resolving dependencies...
Checking inter-conflicts...
Download of manjaro-keyring (20220504-2) started
Download of manjaro-keyring (20220504-2) finished
Checking keyring... [1/1]
Checking integrity... [1/1]
Loading package files... [1/1]
Checking file conflicts... [1/1]
Checking available disc space... [1/1]
Upgrading manjaro-keyring (20220503-1 -> 20220504-2)... [1/1]
==> Appending keys from manjaro.gpg...
==> Disabling revoked keys in keyring...
-> Disabled 1 keys.
==> Updating trust database...
gpg: marginals needed: 3 completes needed: 1 trust model: pgp
gpg: depth: 0 valid: 1 signed: 27 trust: 0-, 0q, 0n, 0m, 0f, 1u
gpg: depth: 1 valid: 27 signed: 96 trust: 0-, 0q, 0n, 27m, 0f, 0u
gpg: depth: 2 valid: 89 signed: 33 trust: 89-, 0q, 0n, 0m, 0f, 0u
gpg: next trustdb check due at 2022-05-06
Resolving dependencies...
Checking inter-conflicts...
Download of firefox (100.0-0.1) started
Download of firefox (100.0-0.1) finished
Checking keyring... [1/1]
Checking integrity... [1/1]
Loading package files... [1/1]
Checking file conflicts... [1/1]
Checking available disc space... [1/1]
Upgrading firefox (99.0.1-1 -> 100.0-0.1)... [1/1]
Running post-transaction hooks...
Arming ConditionNeedsUpdate... [1/3]
Updating icon theme caches... [2/3]
Updating the desktop file MIME type cache... [3/3]
Transaction successfully finished.
So it worked and I got Firefox 100 as a bonus ???
I ran the update again and the key has disabled itself.
~ sudo pamac update ✔ 34s
[sudo] password for shamfer:
Preparing...
Synchronizing package databases...
Refreshing manjaro-sway.db...
Error: manjaro-sway.db: manjaro-sway: key "Jonas Strassel <info@jonas-strassel.de>" is disabled
invalid or corrupted database (PGP signature)
Failed to synchronize databases
Warning: lib32-mesa: local (22.0.0-1) is newer than multilib (21.3.8-2)
Nothing to do.
Transaction successfully finished.
Everything seems to work fine, but I am left feeling confused.