airflowctl: Fix datetime.datetime CLI parameter parsing

[guptakushal03]

Fixes datetime.datetime-typed CLI parameter parsing in airflowctl.

Previously, datetime.datetime parameters were mapped directly to the datetime.datetime constructor, causing valid ISO-8601 datetime strings (for example, 2026-07-01 and 2026-07-01T14:30:00) to be rejected by argparse.

This change:

• Adds iso_datetime_type() to parse ISO-8601 datetime strings using datetime.datetime.fromisoformat().
• Updates datetime.datetime-typed CLI arguments to use the parser instead of the bare constructor.
• Adds unit tests covering valid datetime inputs and invalid values that should raise argparse.ArgumentTypeError.

closes: #70232

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Was generative AI tooling used to co-author this PR?

• Yes (ChatGPT)

Generated-by: ChatGPT following the guidelines.

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Important

🛠️ Maintainer triage note for @guptakushal03 · by @potiuk · 2026-08-13 12:55 UTC

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[potiuk]

Thanks — and sorry to close it.

This overlaps #70249, opened the same day, which fixes the same _python_type_from_string type map. #70249 is the broader fix: it repairs both datetime.date and datetime.datetime (this PR covers only datetime.datetime, leaving date-typed parameters still broken), normalises the trailing Z the API actually emits, passes already-typed values through unchanged, and adds an end-to-end test that the generated dagrun list --start-date argument parses.

Going with #70249 so both halves land together rather than in two passes. It has changes requested outstanding, so it isn't finished either — but the shape is the one to build on.

Closing in its favour. The diagnosis was correct, and the argparse.ArgumentTypeError approach matches what #70249 landed on.

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Drafted by an AI assistant and may contain mistakes — if you think this call is wrong, say so and the PR will be reopened; a human maintainer has the final word.

Drafted-by: Claude Code (Opus 5); reviewed by @potiuk before posting