Update actions/upload-artifact action to v4

Author: renovate[bot]

.github/workflows/testing.yml

@@ -77,9 +77,9 @@ jobs:
           make test-cover
 
       - name: Upload coverage
-        uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
+        uses: actions/upload-artifact@50769540e7f4bd5e21e526ee35c689e35e0d6874 # v4.4.0
         with:
-          name: coverage
+          name: coverage-${{ matrix.os }}-${{ matrix.go }}
           path: coverage.*
 
       - name: Run integration test