Use centralised GHA workflow

.github/workflows/semgrep_diff.yml

@@ -5,19 +5,4 @@ on:
 
 jobs:
   semgrep-diff:
-    runs-on: ubuntu-latest
-    container:
-      image: returntocorp/semgrep
-
-    steps:
-      # Step 1: Clone application source code
-      - name: Checkout code
-        uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # v3.1.0
-        with:
-          fetch-depth: 0
-
-      # Step 2: Differential scan
-      - name: Differential scan
-        run: |
-          semgrep ci \
-            --config="p/trailofbits"
+    uses: adoptium/.github/.github/workflows/semgrep_diff.yml@main