bpo-40243: Use numeric_changed for UCD.numeric

[wmeehan]

This was causing ucd_3_2_0.numeric() to pick up only decimal
changes between Unicode 3.2.0 and the current version.

https://bugs.python.org/issue40243

[ezio-melotti]

This was causing ucd_3_2_0.numeric() to pick up only decimal changes between Unicode 3.2.0 and the current version.

@wmeehan: can you elaborate a bit more on this?

[python-cla-bot]

All commit authors signed the Contributor License Agreement.

[serhiy-storchaka]

LGTM. 👍

Thank you for your contribution, @wmeehan. I apologize that it took so long to do the review.

There was a reorganization in tests, so I rewrote them.

[miss-islington-app]

Thanks @wmeehan for the PR, and @serhiy-storchaka for merging it 🌮🎉.. I'm working now to backport this PR to: 3.13, 3.14.
🐍🍒⛏🤖

[miss-islington-app]

Sorry, @wmeehan and @serhiy-storchaka, I could not cleanly backport this to 3.14 due to a conflict.
Please backport using cherry_picker on command line.

cherry_picker 3e0322ff16f47caa3e273d453f007d3918b8ac80 3.14

[miss-islington-app]

Sorry, @wmeehan and @serhiy-storchaka, I could not cleanly backport this to 3.13 due to a conflict.
Please backport using cherry_picker on command line.

cherry_picker 3e0322ff16f47caa3e273d453f007d3918b8ac80 3.13

[bedevere-app]

GH-144731 is a backport of this pull request to the 3.14 branch.

[bedevere-app]

GH-144732 is a backport of this pull request to the 3.13 branch.