Fix teardown TaskFlow tasks failing on reuse and with expand_kwargs

[surawut-jirasaktavee]

A @teardown TaskFlow task cannot be used twice in a Dag, and mapping one with
expand_kwargs() gives it the wrong trigger rule.

@teardown
def cleanup(x=None): ...

with DAG("example"):
    cleanup()
    cleanup()                            # ValueError: Trigger rule not configurable for teardown tasks.
    cleanup.override(task_id="c2")()     # same ValueError

Cause. __call__ and expand() wrote trigger_rule into the decorator's own
kwargs. The next call, and any .override() copy, saw that stored value as user
input and failed the check meant for users. __call__ also popped
on_failure_fail_dagrun from the same kwargs, so a value set through
.override(on_failure_fail_dagrun=True) applied only to the first call.

expand_kwargs() had no teardown handling at all. A teardown mapped with it got
all_success instead of all_done_setup_success, so it was skipped when an
upstream task failed.

Fix. Both paths now work on a copy of the decorator's kwargs. The teardown
check and trigger rule are applied in one helper, called from __call__ and from
_expand(), which serves both expand() and expand_kwargs(). The error message
is unchanged.

Tests. I added five tests to task-sdk/tests/task_sdk/definitions/decorators/test_setup_teardown.py.
All five fail without the fix.

• Reusing a teardown after a first __call__ or expand(), with the second use through .override(task_id=...).
• on_failure_fail_dagrun set through .override() is kept on a second call.
• expand_kwargs() sets all_done_setup_success.
• expand_kwargs() rejects a user-supplied trigger_rule on a teardown, as expand() does.

Checks run locally:

• task-sdk/tests/task_sdk/definitions/decorators/ and task-sdk/tests/task_sdk/bases/test_decorator.py: 137 passed.
• breeze testing task-sdk-tests, the core tests with and without the database, the provider tests with the database, and breeze build-docs all pass.
• In Breeze, 23 setup/teardown, override and expand tests in providers/standard/tests/unit/standard/decorators/ pass.
• prek passes for both the pre-commit and the manual stages.
• The full non-database provider run did not complete locally because of xdist collection errors in unrelated providers; I'm relying on CI for that part.

closes: #74756

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[fat-catTW]

Thanks for the work!