docs: update Dockerfile

[igoropaniuk]

Fix issues in Dockerfile:

1. Update Fedora image to the latest version 41, otherwise docker build fails with an error:

Step 1/7 : FROM registry.fedoraproject.org/fedora:28
manifest for registry.fedoraproject.org/fedora:28 not found: manifest unknown: manifest unknown

2. Force install python3-yaml package, as it's required for running some tests. For example, tests/test-remote-headers.sh will fail without it:

V=$($CMD_PREFIX ostree --version | \ python3 -c 'import sys, yaml; print(yaml.safe_load(sys.stdin)["libostree"]["Version"])') 
Traceback (most recent call last): 
File "<string>", line 1, in <module> 
import sys, yaml; print(yaml.safe_load(sys.stdin)["libostree"]["Version"])
^^^^^^^^^^^^^^^^
ModuleNotFoundError: No module named 'yaml'

With these fixes make check executes successfully in a container:

============================================================================ 
Testsuite summary for libostree 2024.11
============================================================================
 TOTAL: 935
 PASS:  888
 SKIP:  47
 XFAIL: 0
 FAIL:  0
 XPASS: 0
 ERROR: 0

[openshift-ci]

Hi @igoropaniuk. Thanks for your PR.

I'm waiting for a ostreedev member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[igoropaniuk]

Let me know if there is anything else for me to do in the scope of this change

[cgwalters]

Thank you!