Clean up typed attr() data

[ddbeck]

Summary

This a stopgap for fixing false status calculations for attr() support in web-features, ahead of completing the work in #26624. Specifically, this:

• Cascades data from css.types.attr.type-or-unit to descendants (Chrome 133)
• Remove css.types.attr.type-or-unit.url and css.types.attr.type-or-unit.frequency

Test results and supporting details

• Test cases (by me): https://codepen.io/ddbeck/pen/emJwRgg

• css.types.attr.type-or-unit.url is forbidden by specification:

  Using an attr()-tainted value as or in a makes a declaration invalid at computed-value time.

• The <frequency> type was removed as unimplemented in Remove <frequency> and <frequency-percentage> CSS types #24969. It doesn't make sense to retain data about a type that, functionally, does not exist.

Related issues

• attr() types should reflect support in Chrome 133+ web-platform-dx/web-features#3512
• css.types.attr - Table content not up-to date with latest spec #25618
• css.types.attr - Incorrect support data for <type-or-unit> of attr() #26630
• Sync css.types.attr with CSS Values 5 extensions #26624

[github-actions]

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