Add cache to Documenter.yml

Author: timholy

.github/workflows/Documenter.yml

@@ -9,10 +9,14 @@ jobs:
   Documenter:
     name: Documentation
     runs-on: ubuntu-latest
+    permissions: # needed to allow julia-actions/cache to proactively delete old caches that it has created
+      actions: write
+      contents: read
     steps:
-      - uses: actions/checkout@v2
-      - uses: julia-actions/julia-buildpkg@latest
-      - uses: julia-actions/julia-docdeploy@latest
+      - uses: actions/checkout@v4
+      - uses: julia-actions/cache@v2
+      - uses: julia-actions/julia-buildpkg@v1
+      - uses: julia-actions/julia-docdeploy@v1
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           DOCUMENTER_KEY: ${{ secrets.DOCUMENTER_KEY }}