Run 'cabal update' before build

Author: alexfmpe

.github/workflows/haskell.yml

@@ -33,7 +33,9 @@ jobs:
     - name: Install dependencies
       run: cabal build --only-dependencies --enable-tests --enable-benchmarks
     - name: Build
-      run: cabal build --enable-tests --enable-benchmarks all
+      run: |
+        cabal update
+        cabal build --enable-tests --enable-benchmarks all
     - name: Run tests
       run: cabal test --enable-tests all
     - if: matrix.ghc != '8.4.4'