Update UTU Trust

[Montoya]

This closes #1433

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Note

Low Risk
Low risk: only updates a registry entry (URL + version checksum) with no code or runtime logic changes.

Overview
Updates the npm:@ututrust/utu-metamask-snap entry in src/registry.json by changing the listed website URL and adding a new 1.10.15 version with its checksum.

^{Written by Cursor Bugbot for commit 70f46cb. This will update automatically on new commits. Configure here.}