CI: add dist-newstyle cache

Since we now build all targets here - we may as well cache the `dist-newstyle` here.

Author: Anton-Latukha

.github/workflows/cache.yml

@@ -108,6 +108,18 @@ jobs:
                 ${{ env.cache-name }}-${{ runner.os }}-${{ matrix.ghc }}-
                 ${{ env.cache-name }}-${{ runner.os }}-
 
+      - name: dist-newstyle cache
+        uses: actions/cache@v2
+        env:
+          cache-name: dist-newstyle
+        with:
+          path: ${{ steps.HaskEnvSetup.outputs.cabal-store }}
+          key:  ${{ env.cache-name }}-${{ runner.os }}-${{ matrix.ghc }}-${{ env.HACKAGE_TIMESTAMP }}-${{ hashFiles('cabal.project') }}
+          restore-keys: |
+                ${{ env.cache-name }}-${{ runner.os }}-${{ matrix.ghc }}-${{ env.HACKAGE_TIMESTAMP }}-
+                ${{ env.cache-name }}-${{ runner.os }}-${{ matrix.ghc }}-
+                ${{ env.cache-name }}-${{ runner.os }}-
+
       - name: Download all sources
         run: |
           cabal v2-build all --only-download