Update build.yml

Updating the GH actions to the latest versions to fix deprecation warnings.

.github/workflows/build.yml

@@ -16,18 +16,18 @@ jobs:
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Configure staging build
         run: sed -i 's/https:\/\/rism\.info/https:\/\/stage\.rism\.info/g' _config.yml
         if: endsWith(github.ref, '/staging')
 
       # Use GitHub Actions' cache to shorten build times and decrease load on servers
-      - uses: actions/cache@v2.1.0
+      - uses: actions/cache@v3
         with:
           path: vendor/bundle
           key: ${{ runner.os }}-gems-${{ hashFiles('**/Gemfile.lock') }}-v2
           restore-keys: |
             ${{ runner.os }}-gems-v2
 
       # Tune the jekyll action
-      - uses:  lemonarc/[email protected]
+      - uses:  lemonarc/[email protected]