More robust CI stack dependency caching

Author: sol

.github/workflows/tests.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - run: stack test --resolver nightly --haddock --no-haddock-deps --lock-file read-write --system-ghc --dry-run
+      - run: stack dot --global-hints --resolver nightly --lock-file read-write
       - uses: actions/cache@v4
         with:
           path: ~/.stack