sonar: stop counting the locale table as duplicated code (#3805)

sonar-project.properties

@@ -1,2 +1,6 @@
 sonar.projectKey=storytold_gridcraft
 sonar.organization=storytold
+
+# The region table is one record per locale with the same field names and many shared values
+# (month names, formats); that repetition is data, not copy-pasted logic.
+sonar.cpd.exclusions=crates/core/src/region.rs