modules: fix format-strings without interpolation

Fix all occurrences of format-strings without any interpolation. pylint
warns about those (and for some reason did not do so for our modules).
A followup will fix the pylint tests, so make sure all the warnings are
resolved.

sources/org.osbuild.ostree

@@ -9,7 +9,7 @@ import uuid
 
 def ostree(*args, _input=None, **kwargs):
     args = list(args) + [f'--{k}={v}' for k, v in kwargs.items()]
-    print(f"ostree " + " ".join(args), file=sys.stderr)
+    print("ostree " + " ".join(args), file=sys.stderr)
     subprocess.run(["ostree"] + args,
                    encoding="utf-8",
                    stdout=sys.stderr,