code: def get_tag_date(tag: str) -> str | None:
      """
      Returns UTC timestamp of the tag in the repo in iso time format 8601
      :param tag: tag to get date for
      :return: iso time format 8601 of the tag date
      """
      from git import Repo
  
      repo = Repo(AIRFLOW_SOURCES_ROOT)
      try:
          tag_object = repo.tags[tag].object
      except IndexError:
          get_console().print(
              f"[warning]Tag {tag} not found in the repository"
          )
          return None
      timestamp: int = (
          tag_object.committed_date
          if hasattr(tag_object, "committed_date")
          else tag_object.tagged_date
      )
      return datetime.utcfromtimestamp(timestamp).strftime(
          "%Y-%m-%dT%H:%M:%SZ"
      )
  
file_path: airflow/dev/breeze/src/airflow_breeze/utils/github.py
imports: from __future__ import annotations
  import re
  import sys
  from datetime import datetime
  from pathlib import Path
  from typing import Any
  from rich.markup import escape
  from airflow_breeze.utils.confirm import Answer, user_confirm
  from airflow_breeze.utils.console import get_console
  from airflow_breeze.utils.path_utils import AIRFLOW_SOURCES_ROOT
  from airflow_breeze.utils.shared_options import get_dry_run
label_desc: Use image node_id 5 for calling a global function with example usage: get_tag_date(tag) and returns: datetime, None