Add in sccache

Author: tstellar

.github/workflows/premerge.yaml

@@ -47,6 +47,15 @@ jobs:
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           fetch-depth: 2
+
+      - name: Setup sccache
+        uses: hendrikmuhs/ccache-action@a1209f81afb8c005c13b4296c32e363431bffea5 # v1.2.17
+        if: startsWith(matrix.runs-on, 'depot')
+        with:
+          max-size: 8G
+          key: ${{ matrix.runs-on }}
+          variant: sccache
+
       - name: Build and Test
         run: |
           git config --global --add safe.directory '*'