Annotated tzinfo example

[ChrisPappalardo]

Change Summary

Add an example and a unit test for custom timezone validation.

Related issue number

#8088

Checklist

• The pull request title is a good summary of the changes - it will be used in the changelog
• Unit tests for the changes exist
• Tests pass on CI
• Documentation reflects the changes where applicable
• My PR is ready to review, please add a comment including the phrase "please review" to assign reviewers

[codspeed-hq]

CodSpeed Performance Report

Merging #9468 will not alter performance

_{Comparing ChrisPappalardo:annotated_tzinfo_example (768ad34) with main (9030415)}

Summary

✅ 13 untouched benchmarks

[ChrisPappalardo]

Tests pass with the following exception:

[sydney-runkle]

Amazing! This is such a great use case for the combination of custom validators, annotated types, and modifying schema with annotated type metadata.

Excited to have this as a reference for a future.

[sydney-runkle]

Nice, thanks for moving things around so this follows the wrap validator pattern!