fix(ci): update actions versions

Author: Morgan Jézéquel

.github/workflows/ci.yml

@@ -41,7 +41,7 @@ jobs:
           COVERAGE: ${{ matrix.coverage }}
       - name: Generate coverage artifact
         if: ${{ matrix.coverage }}
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: docs-coverage
           path: docs/coverage
@@ -59,7 +59,7 @@ jobs:
       - name: Generate Ruby API documentation
         run : bundle exec yard doc
       - name: Generate Ruby API documentation artifact
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: docs-ruby
           path: docs/ruby
@@ -80,12 +80,12 @@ jobs:
       url: ${{ steps.deployment.outputs.page_url }}
     steps:
       - name: Fetch Ruby API documentation artifact
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: docs-ruby
           path: docs/ruby
       - name: Fetch coverage artifact
-        uses: actions/download-artifact@v3
+        uses: actions/download-artifact@v4
         with:
           name: docs-coverage
           path: docs/coverage