Need to cabal update after cache restore

Otherwise the cache restore rolls back the hackage index.

Thanks @fgaz for letting me know.

Also changed formatting to match
https://github.com/haskell-actions/setup?tab=readme-ov-file#model-cabal-workflow-with-caching
more.

.github/workflows/haskell.yml

@@ -13,12 +13,9 @@ jobs:
 
     name: GHC ${{ matrix.ghc }} on ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v3
-    - uses: haskell/actions/setup@v2
-      with:
-        ghc-version: ${{ matrix.ghc }}
-        cabal-version: '3.10.1.0'
+
     - name: Cache
+      # Needs to be an early step so e.g. `cabal update` isn't undone
       uses: actions/cache@v3
       env:
         cache-name: cache-cabal
@@ -31,13 +28,23 @@ jobs:
           ${{ runner.os }}-${{ matrix.ghc }}-
           ${{ runner.os }}
 
+    - uses: actions/checkout@v3
+
+    - uses: haskell/actions/setup@v2
+      with:
+        ghc-version: ${{ matrix.ghc }}
+        cabal-version: '3.10.1.0'
+
     - name: Install dependencies
       run: cabal build --only-dependencies --enable-tests --enable-benchmarks
+
     - name: Build
       run: cabal build --enable-tests --enable-benchmarks all
+
     - name: Run tests
       # We don't run hlint tests, because different versions of hlint have different suggestions, and we don't want to worry about satisfying them all.
       run: cabal test --enable-tests -f-hlint all
+
     - if: matrix.ghc != '8.4.4'
       # docs aren't built on ghc 8.4.4 because some dependency docs don't build on older GHCs
       name: Build Docs