Bump back action versions, including upload-artifact to avoid errors …

…re: duplicate artifact names. We just need to get this working asap, so hopefully bumping the version of the will address potential issues in new versions of upload-artifact.

.github/workflows/tests.yml

@@ -19,7 +19,7 @@ jobs:
 
       - name: Cache Homebrew Bundler RubyGems
         id: cache
-        uses: actions/cache@v4
+        uses: actions/cache@v3
         with:
           path: ${{ steps.set-up-homebrew.outputs.gems-path }}
           key: ${{ matrix.os }}-cache-rubygems-${{ steps.set-up-homebrew.outputs.gems-hash }}
@@ -40,7 +40,7 @@ jobs:
 
       - name: Upload bottles as artifact
         if: always() && github.event_name == 'pull_request'
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v3
         with:
           name: bottles
           path: '*.bottle.*'