[Stable Update] 2021-06-14 - Kernels, Browsers, Mesa, Deepin, Systemd, Gnome Apps 40.2, Pipewire, Haskell

No it’s not.

The guest modules are part of the normal kernel package.

The host-modules are only needed for machines that host / run guest machines (as the name already suggests).

linux54 does not have the vboxsf module. It’s only available from version 5.6 onwards:

https://cateee.net/lkddb/web-lkddb/VBOXSF_FS.html

You can still install the missing module from the VirtualBoxGuestAdditions CD image.
Note that you need package dkms to so that the additions can build the modules…