update CI definition

Author: lemastero

.github/workflows/haskell.yml

@@ -23,7 +23,7 @@ jobs:
         # The last step generates dist-newstyle/cache/plan.json for the cache key.
 
       - name: Restore cached dependencies
-        uses: actions/cache/restore@v3
+        uses: actions/cache/restore@v4
         id: cache
         env:
           key: ${{ runner.os }}-ghc-${{ steps.setup.outputs.ghc-version }}-cabal-${{ steps.setup.outputs.cabal-version }}
@@ -39,7 +39,7 @@ jobs:
 
       # Cache dependencies already here, so that we do not have to rebuild them should the subsequent steps fail.
       - name: Save cached dependencies
-        uses: actions/cache/save@v3
+        uses: actions/cache/save@v4
         # If we had an exact cache hit, trying to save the cache would error because of key clash.
         if: ${{ steps.cache.outputs.cache-hit != 'true' }}
         with: