Update Github Actions for better caching

The current cache key did not use `cabal.project.freeze` nor refer to the GHC version, which led to lots of rebuilds

Author: LaurentRDC

.github/workflows/cabal.yml

@@ -22,24 +22,14 @@ jobs:
       matrix:
         include:
           - ghc-version: "8.10.7"
-            cabal-flags: ""
           - ghc-version: "9.0.2"
-            cabal-flags: ""
           - ghc-version: "9.2.8"
-            cabal-flags: ""
           - ghc-version: "9.4.8"
-            cabal-flags: ""
           - ghc-version: "9.6.7"
-            cabal-flags: ""
           - ghc-version: "9.8.4"
-            cabal-flags: ""
           - ghc-version: "9.10.3"
-            cabal-flags: ""
           - ghc-version: "9.12.2"
-            cabal-flags: ""
           - ghc-version: "9.14.1"
-            # See issue 479 for when we can drop the following flags
-            cabal-flags: "--allow-newer=base --allow-newer=ghc-bignum --allow-newer=containers --allow-newer=template-haskell"
 
     runs-on: "ubuntu-latest"
 
@@ -57,7 +47,7 @@ jobs:
       run: |
         # Cloud Haskell tests using the QUIC backend are quite flaky, but in CI only.
         # Therefore, the 'quic' flag is normally enabled locally, but disabled in CI.
-        cabal configure --test-show-details=direct --flags "-quic" ${{matrix.cabal-flags}}
+        cabal configure --test-show-details=direct --flags "-quic"
         cabal freeze --minimize-conflict-set
         cat cabal.project.freeze
 
@@ -67,9 +57,9 @@ jobs:
         path: |
           dist-newstyle
           ${{ steps.setup-haskell.outputs.cabal-store }}
-        # We are using the hash of 'cabal.project.local' so that different levels
-        # of optimizations are cached separately
-        key: ${{ runner.os }}-${{ hashFiles('cabal.project', 'cabal.project.local') }}-cabal-install
+        key: ${{ runner.os }}-ghc-${{ matrix.ghc-version }}-${{ hashFiles('cabal.project', 'cabal.project.freeze') }}
+        restore-keys: |
+          ${{ runner.os }}-ghc-${{ matrix.ghc-version }}-
 
     - name: Build dependencies only
       run: cabal build all --only-dependencies