test/test_repo_utils: correctly parse system git version

[kshtsk]

On macos there are bunch of tests fails because system git version output cannot be parsed because of extra ending.

Output example for macOS:

   git version 2.39.3 (Apple Git-146)

Output example for linux:

   git version 2.45.2

[kshtsk]

This is how it looks like before the fix:

========================================================================== short test summary info ==========================================================================
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_clone_repo_existing_branch - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_clone_repo_non_existing_branch - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_fetch_no_repo - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_fetch_noop - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_fetch_branch_no_repo - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_fetch_branch_fake_branch - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_fetch_branch_different_git_versions[fatal: couldn't find remote ref] - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_fetch_branch_different_git_versions[fatal: Couldn't find remote ref] - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_enforce_existing_branch - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_enforce_existing_commit - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_enforce_non_existing_branch - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_enforce_non_existing_commit - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_enforce_multiple_calls_same_branch - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_enforce_multiple_calls_different_branches - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_enforce_invalid_branch - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_simultaneous_access - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_simultaneous_access_different_branches - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_url_to_dirname[[email protected]/ceph-qa-suite.git-git.ceph.com_ceph-qa-suite] - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_url_to_dirname[git://git.ceph.com/ceph-qa-suite.git-git.ceph.com_ceph-qa-suite] - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_url_to_dirname[https://github.com/ceph/ceph-github.com_ceph_ceph] - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_url_to_dirname[https://github.com/liewegas/ceph.git-github.com_liewegas_ceph] - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_url_to_dirname[file:///my/dir/has/ceph.git-my_dir_has_ceph] - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
ERROR teuthology/test/test_repo_utils.py::TestRepoUtils::test_current_branch - packaging.version.InvalidVersion: Invalid version: 'Git-146)'
=================================================== 1053 passed, 87 skipped, 13 warnings, 23 errors in 251.17s (0:04:11) ====================================================

[zmc]

I use homebrew's git so I never saw this! Thank you.