[Bug]: CLI: `TypeError: HEAD is a detached symbolic reference` when repo is checked out with a tag

[un-def]

Steps to reproduce

1. Clone dstack repo
2. git checkout 0.20.15
3. dstack apply -f examples/.dstack.yml

Actual behaviour

Traceback (most recent call last):
  File "dstack/.venv/bin/dstack", line 10, in <module>
    sys.exit(main())
             ~~~~^^
  File "dstack/src/dstack/_internal/cli/main.py", line 97, in main
    args.func(args)
    ~~~~~~~~~^^^^^^
  File "dstack/src/dstack/_internal/cli/commands/apply.py", line 98, in _command
    configurator.apply_configuration(
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^
        conf=configuration,
        ^^^^^^^^^^^^^^^^^^^
    ...<2 lines>...
        configurator_args=configurator_args,
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    )
    ^
  File "dstack/src/dstack/_internal/cli/services/configurators/run.py", line 101, in apply_configuration
    repo = self.get_repo(conf, configuration_path, configurator_args)
  File "dstack/src/dstack/_internal/cli/services/configurators/run.py", line 550, in get_repo
    repo = get_repo_from_dir(local_path)
  File "dstack/src/dstack/_internal/cli/services/repos.py", line 44, in get_repo_from_dir
    return RemoteRepo.from_dir(repo_dir)
           ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "dstack/src/dstack/_internal/core/models/repos/remote.py", line 117, in from_dir
    return RemoteRepo(local_repo_dir=repo_dir)
  File "dstack/src/dstack/_internal/core/models/repos/remote.py", line 155, in __init__
    tracking_branch = repo.active_branch.tracking_branch()
                      ^^^^^^^^^^^^^^^^^^
  File "dstack/.venv/lib/python3.13/site-packages/git/repo/base.py", line 1054, in active_branch
    return self.head.reference
           ^^^^^^^^^^^^^^^^^^^
  File "dstack/.venv/lib/python3.13/site-packages/git/refs/symbolic.py", line 506, in reference
    return self._get_reference()
           ~~~~~~~~~~~~~~~~~~~^^
  File "dstack/.venv/lib/python3.13/site-packages/git/refs/symbolic.py", line 418, in _get_reference
    raise TypeError("%s is a detached symbolic reference as it points to %r" % (self, sha))
TypeError: HEAD is a detached symbolic reference as it points to '6f1f1f41848735c3a1c0d16a9efc8fdf291caca0'

Expected behaviour

No response

dstack version

0.20.15

Server logs

Additional information

No response