Exclude workflow files from Sonar duplication checks

Author: krotname

sonar-project.properties

@@ -1,3 +1,3 @@
 # Kata and algorithm exercise solutions naturally repeat short structural patterns.
 # Keep SonarCloud issue/security analysis, but exclude these training folders from CPD.
-sonar.cpd.exclusions=src/main/java/kyu*/**/*,src/main/java/algorithms/**/*,src/test/java/**/*
+sonar.cpd.exclusions=src/main/java/kyu*/**/*,src/main/java/algorithms/**/*,src/test/java/**/*,.github/**/*