use Codecov token

already needed since cdbff26
(cf. https://docs.codecov.com/docs/codecov-tokens &
https://github.com/marketplace/actions/codecov#v4-release:
"Breaking Changes [of v4]: Tokenless uploading is unsupported" 🙈)

obtained from https://app.codecov.io/gh/TNG/property-loader/config/general,
stored at https://github.com/TNG/property-loader/settings/secrets/actions

Signed-off-by: Manfred Hanke <Manfred.Hanke@tngtech.com>

Author: hankem

.github/workflows/build.yml

@@ -27,6 +27,7 @@ jobs:
         with:
           files: build/reports/jacoco/test/jacocoTestReport.xml
           name: codecov
+          token: ${{ secrets.CODECOV_TOKEN }}
 
   dependency-check:
     needs: test