Update outdated GH Actions

Author: jakejackson1

.github/workflows/end-to-end-tests.yml

@@ -107,7 +107,7 @@ jobs:
           mv tmp screenshots/tmp
 
       - name: Upload artifacts on failure
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         if: failure()
         with:
           name: my-artifact

.github/workflows/phpunit.tests.yml

@@ -146,7 +146,10 @@ jobs:
           yarn run test:php --group ajax --do-not-cache-result --verbose --coverage-clover=/var/www/html/wp-content/plugins/gravity-pdf/tmp/coverage/report-xml/php-coverage2.xml
 
       - name: Code Coverage Upload
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v4
         if: ${{ matrix.report }}
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
         with:
           files: tmp/coverage/report-xml/php-coverage1.xml
+