Revert to action v3

Author: Andrea Scuderi

.github/workflows/swift-test.yml

@@ -39,9 +39,7 @@ jobs:
       - name: Coverage
         run: |
           make coverage
-      - name: Upload coverage reports to Codecov
-        uses: codecov/codecov-action@v4.0.1
+      - name: Upload Code Coverage 
+        uses: codecov/codecov-action@v3
         with:
-          token: ${{ secrets.CODECOV_TOKEN }}
-          slug: swift-serverless/BreezeLambdaWebHook
           files: ${{ github.workspace }}/lcov.info