docs: add number input to date input example

[SR0725]

What I changed

• added an HTML number input to the existing date-input gallery example
• used the date value to filter the x-axis range and the minimum visitor count to filter y-axis values
• kept matching arguments-syntax and methods-syntax versions
• removed the separate number-input example so the related controls stay on one gallery page

This covers the number-input example suggested in #3403 without adding another gallery entry.

Testing

• uv run --frozen pytest tests/test_examples.py -k interactive_date_input -q -n0 -p no:cacheprovider (6 passed)
• uv run --frozen task ruff-check
• uv run --frozen task doc-build -- --clean --no-autosummary (build succeeded with one warning in doc/gallery/index.rst, which this PR does not modify)

[joelostblom]

Thanks for the PR @SR0725 ! Instead of making a new example, I wonder if we can combine this with the recently added example from #4088? Could you add the number input there as well and have it filter the y-axis? Or feel free to come up with a new example that can combine both. We have quite a lot of gallery examples, so it would be nice if related functionality like this can be in the same example.

[SR0725]

That makes sense. I folded the number input into interactive_date_input: the date parameter filters the x-axis range, and minimum_visitors filters the y values. I also removed the standalone number-input files. The focused example tests pass 6/6, ruff passes, and the local docs build succeeds. Updated in 10f2e20.