Make session parameter in dag_clear CLI keyword only

[jason810496]

• related: feat(cli): add airflow dags clear for partition-range reprocessing #66004
• fail run: https://github.com/apache/airflow/actions/runs/26440852647/job/77843698384?pr=67150

What

• The Add prek hook to enforce keyword-only session on @provide_session #67150 static check catched the new violation in dag_clear CLI command introduced yesterday.

Check that no new @provide_session functions declare `session` positionally...............................Failed
- hook id: check-no-new-provide-session-positional
- exit code: 1

  ╭────────────────────────────────────── Check failed ──────────────────────────────────────╮
  │ New @provide_session function with positional ``session`` detected.                      │
  │ Move ``session`` after a bare ``*`` in the signature so callers must pass it by keyword: │
  │                                                                                          │
  │   @provide_session                                                                       │
  │   def foo(arg, *, session: Session = NEW_SESSION) -> None: ...                           │
  │                                                                                          │
  │ If this usage is intentional and pre-existing, run:                                      │
  │                                                                                          │
  │   uv run ./scripts/ci/prek/check_provide_session_kwargs.py --generate                    │
  │                                                                                          │
  │ to regenerate the allowlist, then commit the updated                                     │
  │ scripts/ci/prek/known_provide_session_positional.txt.                                    │
  ╰──────────────────────────────────────────────────────────────────────────────────────────╯
    airflow-core/src/airflow/cli/commands/dag_command.py  count=9 (allowed=8)
        L128 def dag_clear(...)
        L365 def dag_state(...)
        L476 def dag_list_dags(...)
        L564 def dag_details(...)
        L586 def dag_list_import_errors(...)
        L675 def dag_list_jobs(...)
        L706 def dag_list_dag_runs(...)
        L744 def dag_test(...)
        L802 def dag_reserialize(...)

[Prab-27]

Let's wait for CI