ICU-22724 Update urename.h for ICU 76.1 final.

[richgillam]

Regenerated urename.h one last time (I hope) before the final ICU 76.1 release. There was one change from the rc.

Checklist

• Required: Issue filed: https://unicode-org.atlassian.net/browse/ICU-22724
• Required: The PR title must be prefixed with a JIRA Issue number. Example: "ICU-1234 Fix xyz"
• Required: The PR description must include the link to the Jira Issue, for example by completing the URL in the first checklist item
• Required: Each commit message must be prefixed with a JIRA Issue number. Example: "ICU-1234 Fix xyz"
• Issue accepted (done by Technical Committee after discussion)
• Tests included, if applicable
• API docs and/or User Guide docs changed or added, if applicable