ci: use cached build for slither job

.github/workflows/ci.yml

@@ -299,6 +299,16 @@ jobs:
         with:
           submodules: "recursive"
 
+      - name: "Restore the cached build"
+        uses: "actions/cache/restore@v3"
+        with:
+          fail-on-cache-miss: true
+          key: "foundry-build-${{ github.sha }}"
+          path: |
+            cache
+            out
+            out-optimized
+
       - name: "Run Slither analysis"
         uses: "crytic/[email protected]"
         id: "slither"
@@ -307,6 +317,7 @@ jobs:
           sarif: "results.sarif"
           solc-version: "0.8.19"
           target: "src/"
+          ignore-compile: true
 
       - name: "Upload SARIF file to GitHub code scanning"
         uses: "github/codeql-action/upload-sarif@v2"