CI "Check Field Syntax Reference": correct cache key

.github/workflows/quick-jobs.yml

@@ -113,16 +113,32 @@ jobs:
   buildinfo:
     name: Check Field Syntax Reference
     runs-on: ubuntu-latest
+    env:
+      cabal_build: cabal build buildinfo-reference-generator
     steps:
-      - uses: actions/cache@v4
-        with:
-          path: ~/.local/state/cabal
-          key: linux-store-buildinfo-doc-diff
       - name: Update Hackage index
         run: cabal v2-update
       - uses: actions/checkout@v4
+      - name: Generate build plan for correct cache key
+        run: ${{ env.cabal_build }} --dry-run
+      - name: Restore cached dependencies
+        uses: actions/cache/restore@v4
+        id: cache
+        with:
+          path: ~/.local/state/cabal
+          key: linux-store-buildinfo-doc-diff-${{ hashfiles('dist-newstyle/cache/plan.json') }}
+          restore-keys: linux-store-buildinfo-doc-diff
+      - name: Build buildinfo-reference-generator
+        run: ${{ env.cabal_build }}
       - name: Are buildinfo docs up to date?
         run: make doc/buildinfo-fields-reference.rst
+      - name: Cache dependencies
+        uses: actions/cache/save@v4
+        if: always() && steps.cache.outputs.cache-hit != 'true'
+        with:
+          path: ~/.local/state/cabal
+          key: ${{ steps.cache.outputs.cache-primary-key }}
+
   release-project:
     name: Check Release Project
     runs-on: ubuntu-latest