update-CI: add caching of the store

Author: ulysses4ever

.github/workflows/update-haskell-ci-on-tested-with-pr.yml

@@ -69,10 +69,27 @@ jobs:
       - name: Set up Haskell toolchain
         uses: haskell-actions/setup@v2
 
-      - name: Install haskell-ci
+      - name: Clone haskell-ci sources
+        shell: bash
         run: |
           set -euxo pipefail
           git clone --depth 1 https://github.com/haskell-CI/haskell-ci.git .tooling/haskell-ci
+
+      # Cache Cabal store and haskell-ci build artifacts
+      - name: Cache Cabal store and dist-newstyle for haskell-ci
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cabal/store
+            .tooling/haskell-ci/dist-newstyle
+          key: ${{ runner.os }}-cabalstore-ghc-${{ env.GHC_VERSION }}-cabal-${{ env.CABAL_VERSION }}-${{ hashFiles('.tooling/haskell-ci/**/*.cabal', '.tooling/haskell-ci/cabal.project*') }}
+          restore-keys: |
+            ${{ runner.os }}-cabalstore-ghc-${{ env.GHC_VERSION }}-cabal-${{ env.CABAL_VERSION }}-
+
+      - name: Build and install haskell-ci
+        shell: bash
+        run: |
+          set -euxo pipefail
           cd .tooling/haskell-ci
           cabal update
           cabal build exe:haskell-ci