cmdlib: also chown back compose.json in privileged path

[jlebon]

Match what we do for the repo and chown back compose.json to the build user. This should fix cosa build --force-image.

[dustymabe]

LGTM

but.. TBH I'm almost of mind that the followup targets thing should be dropped from this code and we just rely on either cosa osbuild or cosa buildextend in the future, both of which have --force.

[jlebon]

/retest

[jlebon]

but.. TBH I'm almost of mind that the followup targets thing should be dropped from this code and we just rely on either cosa osbuild or cosa buildextend in the future, both of which have --force.

Hmm, --force-image is a weirdly-named option, but it's mostly unrelated to the followup targets logic. cosa build is the only command capable of creating new builds. Currently, a change to e.g. image.yaml must result in a new build. But we want to be smart enough to not rebuild the ostree as well. But sometimes, the change detection logic might not be smart enough to know that an image input has changed and a new build ID must be allocated, and that's where --force-image can be useful. A perfect example is actually for testing #3861, where I wanted to do two builds in a row, one with the legacy path, and one with the osbuild path, to compare them.

[dustymabe]

Some fallout.. Multi-arch builds are failing in the cosa fetch with:

chown: cannot access '/home/jenkins/agent/workspace/build-arch/tmp/compose.json': No such file or directory

[jlebon]

Some fallout.. Multi-arch builds are failing in the cosa fetch with:

chown: cannot access '/home/jenkins/agent/workspace/build-arch/tmp/compose.json': No such file or directory

Fixup in #3969!