Bug: atomfs umount failure in test

[raharper]

stacker version

130ce6d

Describe the bug

# mountinfo after umount a^
# Debug mode:
# stacker version 130ce6de6f2b89eb742c490b4f8a66f013deece9
# stacker subcommand: [/home/runner/work/stacker/stacker/stacker --debug internal-go atomfs umount c]
# Device /dev/mapper/a86779c84f2284edd841afd66028ea3a4127f0a99e93ec975a60dfc54f112c96-verity is still in use.
# Device /dev/mapper/bc2724c2f7dfb5e0955313d07544e68f68a98c2365ed80ece60ba49e85a0f307-verity is still in use.
# Device /dev/mapper/e73743ff1b2d38943234dd9038522808063f721074215527496f624fcdceb78d-verity is still in use.
# Device /dev/mapper/e73743ff1b2d38943234dd9038522808063f721074215527496f624fcdceb78d-verity is still in use.
# Device /dev/mapper/e73743ff1b2d38943234dd9038522808063f721074215527496f624fcdceb78d-verity is still in use.
# Device /dev/mapper/e73743ff1b2d38943234dd9038522808063f721074215527496f624fcdceb78d-verity is still in use.
# Device /dev/mapper/e73743ff1b2d38943234dd9038522808063f721074215527496f624fcdceb78d-verity is still in use.
# Error: failed verity-unmounting /dev/mapper/e73743ff1b2d38943234dd9038522808063f721074215527496f624fcdceb78d-verity: libcryptsetup function 'crypt_deactivate' returned error with code '-16'.
# machinerun.io/atomfs/pkg/common.MaybeCleanupBackingDevice
# 	/stacker-tree/.build/gopath/pkg/mod/machinerun.io/atomfs@v1.2.0/pkg/common/mount.go:95
# machinerun.io/atomfs/pkg/molecule.UmountWithMetadir
# 	/stacker-tree/.build/gopath/pkg/mod/machinerun.io/atomfs@v1.2.0/pkg/molecule/molecule.go:412
# machinerun.io/atomfs/pkg/molecule.Umount
# 	/stacker-tree/.build/gopath/pkg/mod/machinerun.io/atomfs@v1.2.0/pkg/molecule/molecule.go:299
# main.doAtomfsUmount
# 	/stacker-tree/cmd/stacker/internal_go.go:202

To reproduce

1. Configuration

default

2. Client tool used

make test

3. Seen error

Expected behavior

No response

Screenshots

No response

Additional context

No response