[CI/Build] remove .github from .dockerignore, add dirty repo check

[dtrifiro]

Including .github in .dockerignore results having a dirty repo when copying the source while building the image, causing the version string setuptools-scm not to match tags exactly.

Also include tools/check_repo.sh to check repo status before building.

See context here

[github-actions]

👋 Hi! Thank you for contributing to the vLLM project.
Just a reminder: PRs would not trigger full CI run by default. Instead, it would only run fastcheck CI which starts running only a small and essential subset of CI tests to quickly catch errors. You can run other CI tests on top of those by going to your fastcheck build on Buildkite UI (linked in the PR checks section) and unblock them. If you do not have permission to unblock, ping simon-mo or khluu to add you in our Buildkite org.

Once the PR is approved and ready to go, your PR reviewer(s) can run CI to test the changes comprehensively before merging.

To run CI, PR reviewers can do one of these:

• Add ready label to the PR
• Enable auto-merge.

🚀

[simon-mo]

Can we add a clause in Dockerfile to assert the git repo is in non dirty state (gated by a flag off by default, and turned on by release, similar to wheel size check, although wheel size check is on by default)

[simon-mo]

Actually in all our ci it shouldn't be dirty

[dtrifiro]

Can we add a clause in Dockerfile to assert the git repo is in non dirty state (gated by a flag off by default, and turned on by release, similar to wheel size check, although wheel size check is on by default)

Added a clause to check for git repo status (dirty and presence of tags) under the --build-arg GIT_REPO_CHECK=1

[simon-mo]

Let's revert the non default Dockerfile changes? I believe given those don't get triggered in release pipeline we don't need to do that.

[simon-mo]

[2024-10-17T17:13:54Z] #18 [build 4/8] RUN --mount=type=bind,source=.git,target=.git if [ "1" != 0 ]; then bash tools/check_repo.sh ; fi

  | [2024-10-17T17:13:55Z] #18 0.638 v0.6.3-10-gb007d160
  | [2024-10-17T17:13:55Z] #18 DONE 0.7s

Build pass here https://buildkite.com/vllm/release/builds/1409#01929b76-e6c7-479c-9b7c-f6e25653eec9