Cache the Nix store for improved runtime

Author: rvermeulen

.github/workflows/codeql.yml

@@ -22,6 +22,18 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
+      - name: Cache Nix Store
+        uses: actions/cache@v4
+        id: cache
+        with:
+          path: /nix/store
+          key: ${{ runner.os }}-${{ hashFiles('tooling/**') }}
+
+      - name: Prepare Nix Store
+        if: steps.cache.outputs.cache-hit != 'true'
+        run: |
+          nix-shell --pure --command "codeql version" tooling/shell.nix
+
       - name: Create database
         run: |
           nix-shell --pure --command "codeql database create --language=ql --source=. $RUNNER_TEMP/ql-db" tooling/shell.nix