Merge pull request #77 from zcash/ga

Update gh-pages.yml

.github/workflows/gh-pages.yml

@@ -32,7 +32,7 @@ jobs:
         run: echo "::set-output name=dir::$(pip cache dir)"
 
       - name: Cache dependencies
-        uses: actions/cache@v2
+        uses: actions/cache@v4
         with:
           path: ${{ steps.pip-cache.outputs.dir }}
           key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt') }}