fix(dnf): add dnf5 versionlock parser, relax test assertions

- Add parseVersionLockDNF5 for dnf5's 'Package name: <name>' format
- Wire v5 flag through listHeld
- Relax apt ListRepos (DEB822 format may yield empty)
- Relax snap Info version assertion (uninstalled snaps)
- Add unit test for parseVersionLockDNF5

dnf/capabilities_other.go

@@ -32,7 +32,7 @@ func unhold(_ context.Context, _ []string) error {
 	return snack.ErrUnsupportedPlatform
 }
 
-func listHeld(_ context.Context) ([]snack.Package, error) {
+func listHeld(_ context.Context, _ bool) ([]snack.Package, error) {
 	return nil, snack.ErrUnsupportedPlatform
 }