All you should have to do is remove the call(s) that tries to mount the snap files at bootup. These files are contained in the /etc/systemd/system/ directory.
Remove the snap .mount file(s) for the one(s) you don't want.
Example:
terrance@terrance-ubuntu:/etc/systemd/system$ ls *.mount
snap-bare-5.mount
snap-bitwarden-84.mount
snap-bitwarden-85.mount
'snap-canonical\x2dlivepatch-146.mount'
'snap-canonical\x2dlivepatch-164.mount'
snap-code-122.mount
snap-code-123.mount
snap-core-14784.mount
snap-core-14946.mount
snap-core18-2714.mount
snap-core18-2721.mount
snap-core20-1828.mount
snap-core20-1852.mount
snap-core22-547.mount
snap-core22-583.mount
snap-cups-872.mount
'snap-gnome\x2d3\x2d28\x2d1804-161.mount'
'snap-gnome\x2d3\x2d28\x2d1804-194.mount'
'snap-gnome\x2d3\x2d38\x2d2004-119.mount'
'snap-gnome\x2d3\x2d38\x2d2004-137.mount'
'snap-gtk2\x2dcommon\x2dthemes-13.mount'
'snap-gtk\x2dcommon\x2dthemes-1535.mount'
snap-snapd-18357.mount
snap-snapd-18596.mount
'snap-snap\x2dstore-599.mount'
'snap-snap\x2dstore-638.mount'
'snap-ubuntu\x2dapp\x2dplatform-34.mount'
snap-warble-5.mount
Within each of these files contains the mount instructions and snap file it is going to mount.
terrance@terrance-ubuntu:/etc/systemd/system$ cat snap-bitwarden-85.mount
[Unit]
Description=Mount unit for bitwarden, revision 85
After=snapd.mounts-pre.target
Before=snapd.mounts.target
Before=local-fs.target
[Mount]
What=/var/lib/snapd/snaps/bitwarden_85.snap
Where=/snap/bitwarden/85
Type=squashfs
Options=nodev,ro,x-gdu.hide,x-gvfs-hide
LazyUnmount=yes
[Install]
WantedBy=snapd.mounts.target
WantedBy=multi-user.target
The easiest way since you are not going to use snaps anymore would be to go to that directory and remove all of the .mount files.
cd /etc/systemd/system
sudo rm -Rf snap*
I chose the sudo rm -Rf snap* command because there is another sub-directory also containing .mount files and since they all start with the word snap, that should cover them all.
After those files are gone you shouldn't see the mount errors anymore.
