[icu] Bump ICU version to 76.1

[shannonbooth]

• Changes comply with the maintainer guide.
• SHA512s are updated for each updated download.
• The "supports" clause reflects platforms that may be fixed by this new version.
• Any fixed CI baseline entries are removed from that file.
• Any patches that are no longer applied are deleted from the port's directory.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is added to each modified port's versions file.

[shannonbooth]

@microsoft-github-policy-service agree

[shannonbooth]

I believe the issue that CI is complaining about is due to unicode-org/icu@b542ae9

And the build machines not having a new enough version of autoconf. What would the suggested approach be for this? Is it acceptable to patch this out to a lower version?

[dg0yt]

I suppose #38826 (comment) is still a blocker.

[shannonbooth]

Ah, I see, thanks! I wasnt able to find that before making this