deps: update osbuild/images to v0.3.0

Bump the required osbuild version to v93 (due to the systemd units
change).

Pin the new osbuild version in Schutzfile.

Update repo snapshots in Schutzfile due to osbuild v93 depending on
new selinux-policy build.

vendor/github.com/osbuild/images/pkg/manifest/commit.go

@@ -16,20 +16,14 @@ type OSTreeCommit struct {
 // NewOSTreeCommit creates a new OSTree commit pipeline. The
 // treePipeline is the tree representing the content of the commit.
 // ref is the ref to create the commit under.
-func NewOSTreeCommit(m *Manifest,
-	buildPipeline *Build,
-	treePipeline *OS,
-	ref string) *OSTreeCommit {
+func NewOSTreeCommit(buildPipeline *Build, treePipeline *OS, ref string) *OSTreeCommit {
 	p := &OSTreeCommit{
-		Base:         NewBase(m, "ostree-commit", buildPipeline),
+		Base:         NewBase(treePipeline.Manifest(), "ostree-commit", buildPipeline),
 		treePipeline: treePipeline,
 		ref:          ref,
 	}
-	if treePipeline.Base.manifest != m {
-		panic("tree pipeline from different manifest")
-	}
 	buildPipeline.addDependent(p)
-	m.addPipeline(p)
+	treePipeline.Manifest().addPipeline(p)
 	return p
 }