Fixed codecov for repository (#909)

## Changes
<!-- Summary of your changes that are easy to understand -->
Same as
databricks/terraform-provider-databricks#3530

## Tests
<!-- 
How is this tested? Please see the checklist below and also describe any
other relevant tests
-->
CI:
`````
info - 2024-05-03 10:00:47,486 -- Found 1 coverage files to report
info - 2024-05-03 10:00:47,486 -- > /home/runner/work/databricks-sdk-go/databricks-sdk-go/coverage.txt
info - 2024-05-03 10:00:48,261 -- Your upload is now processing. When finished, results will be available at: https://app.codecov.io/github/databricks/databricks-sdk-go/commit/fe2a4e7a993c5183e6324e324fa4542dc7b60c9d
info - 2024-05-03 10:00:48,5[47](https://github.com/databricks/databricks-sdk-go/actions/runs/8937140473/job/24549255623?pr=909#step:7:48) -- Process Upload complete
`````
- [ ] `make test` passing
- [ ] `make fmt` applied
- [ ] relevant integration tests applied

.github/workflows/push.yml

@@ -46,7 +46,9 @@ jobs:
         run: make test
 
       - name: Publish test coverage
-        uses: codecov/codecov-action@v3
+        uses: codecov/codecov-action@v4
+        env:
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
 
   fmt:
     runs-on: ubuntu-latest