Switch to next release of codecov action now that it has been verified to work.

Author: mattpolzin

.github/workflows/codecov.yml

@@ -11,6 +11,6 @@ jobs:
     - uses: actions/checkout@v2
     - run: swift test --enable-test-discovery --enable-code-coverage
     - id: analysis
-      uses: mattpolzin/swift-codecov-action@master
+      uses: mattpolzin/swift-codecov-action@0.6.0
       with:
         MINIMUM_COVERAGE: 98