chore(codecov-action): update to codecov/codecov-action@v5. Use OIDC …

…instead of codecov token (#33246)

### Issue # (if applicable)

Closes #
Resolve intermittent failures for codecov-action complaining about CODECOV_TOKEN.
https://github.com/aws/aws-cdk/actions/runs/12987465886/job/36314301605 for #33174

### Reason for this change

Resolve intermittent codecov-action failures by upgrading codecov-actions and moving to OIDC instead of codecov token.

### Description of changes
Updated codecov.yml



### Describe any new or updated permissions being added




### Description of how you validated changes
N/A


### Checklist
- [ x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

.github/workflows/codecov.yml

@@ -11,6 +11,8 @@ jobs:
     name: collect
     if: github.repository == 'aws/aws-cdk'
     runs-on: ubuntu-latest
+    permissions:
+      id-token: write
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -34,9 +36,9 @@ jobs:
         run: cd packages/aws-cdk && yarn test
 
       - name: Upload results to Codecov
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v5
         with:
           files: packages/aws-cdk/coverage/cobertura-coverage.xml,packages/aws-cdk-lib/coverage/cobertura-coverage.xml
           fail_ci_if_error: true
           flags: suite.unit
-          token: ${{ secrets.CODECOV_TOKEN }}
+          use_oidc: true