Gitignore git worktree directories (#7143)

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: christophe-papazian

.gitignore

@@ -79,3 +79,7 @@ go.work*
 
 # Hypothesis Python package
 .hypothesis/
+
+# Git worktrees
+.claude/worktrees/
+.worktrees/