Add shared helper for listing Git tags via git ls-remote

[ziadhany]

We currently duplicate logic for listing tags via git ls-remote purl2vcs/find_source_repo.py#L384

Create a single shared helper (e.g. list_tags_via_ls_remote) to avoid duplication and provide consistent behavior.

Refs:

• Add support to mine Swift Package-URLs #725
• GitHubTagsAPI vs GitTagsAPI vulnerablecode#493
• https://github.com/gitpython-developers/GitPython/blob/2d4c54154bc984f5dafde1b23e377e2dc3214cb8/test/lib/helper.py#L307
• minecode_pipelines/miners/swift.py

result = subprocess.run(
            [git_executable, "ls-remote", repo_url],
            capture_output=True,
            text=True,
            check=True,
            timeout=timeout,
)