RFC, feat: infer datetime format for pyarrow backend

[FBruzzesi]

What type of PR is this? (check all applicable)

• 💾 Refactor
• ✨ Feature
• 🐛 Bug Fix
• 🔧 Optimization
• 📝 Documentation
• ✅ Test
• 🐳 Other

Related issues

• Closes [Enh]: Infer datetime format for pyarrow backend in to_datetime(format=None) case #1151

Checklist

• Code follows style guide (ruff)
• Tests added
• Documented the changes

If you have comments or can explain your changes, please do so below.

As discussed in the comment of the PR tagged in the issue, the implementation is inspired by and adjusted from the following repository: datetime-format.

I am opening this as draft and looking for help for:

• Enlarge the test suite with multiple formats, if it would be possible to do this dynamically (maybe with hypothesis it would be great - I never used it though)
• Add other common formats:
  • allow for AM/PM
  • Are there other date separators?
  • Are there other time separators?
  • other?

For the two latter questions, sometimes at work we use no separators e.g. YYYYmmddHHMMSS

PS: CI Failure on doctest is unrelated

[MarcoGorelli]

ooh, nice!

I think this might already be a good start? if we can at least auto-detect iso8601-like formats, that's already an improvement