Add local Claude settings file to gitignore

Local Claude settings contain information specific for a user and
repository, such as specific execution permissions. They are not
supposed to be committed and the according settings file is recommended
to be ignored from Git.

Author: HeikoKlare

.gitignore

@@ -9,3 +9,4 @@ pom.tycho
 /xdg-runtime-*
 /binaries/org.eclipse.swt.*/src/
 tmpdir/
+.claude/settings.local.json