codecov: upgrade tarpaulin 0.31.3

Author: CherishCai

.github/workflows/codecov.yml

@@ -27,5 +27,5 @@ jobs:
           override: true
       - uses: actions-rs/[email protected]
         with:
-          version: 0.22.0
-      - uses: codecov/codecov-action@v2.1.0
+          version: 0.31.3
+      - uses: codecov/codecov-action@v2