Update codeql-build.yml

.github/workflows/codeql-build.yml

@@ -9,6 +9,20 @@ on:
     - cron:  '15 23 * * 0'
 
 jobs:
+  #Checks for duplicate actions. Skips push actions if there is a matching or duplicate pull-request action.
+  check-for-duplicates:
+    runs-on: ubuntu-20.04
+    # Map a step output to a job output
+    outputs:
+      should_skip: ${{ steps.skip_check.outputs.should_skip }}
+    steps:
+      - id: skip_check
+        uses: fkirc/skip-duplicate-actions@master
+        with:
+          concurrent_skipping: 'same_content'
+          skip_after_successful_duplicate: 'true'
+          do_not_skip: '["pull_request", "workflow_dispatch", "schedule"]'
+
   codeql:
     name: Run CodeQL
     runs-on: ${{ github.repository_owner == 'cFS' && 'linux' || 'ubuntu-latest' }}