ci: wire GITHUB_TOKEN + BUILD_NUMBER for Coveralls (github-actions)

The nbaztec coveralls-jacoco v1.2.20 plugin has a quirky GitHub Actions
detection path. Reading its source (ServiceInfoParser.kt):

  - If GITHUB_ACTIONS is set but GITHUB_TOKEN is not, it emits
    service_name="github-actions" — which the Coveralls API does not
    recognize as a first-class service, so PR comments and branch
    correlation silently no-op.
  - When BOTH GITHUB_ACTIONS and GITHUB_TOKEN are set, it switches to
    service_name="github" (the canonical name).
  - service_job_id is read from BUILD_NUMBER (Jenkins-style), not
    GITHUB_RUN_ID — so we map github.run_id onto BUILD_NUMBER explicitly.
  - Branch is read from CI_BRANCH; github.head_ref is used so PR builds
    report the source branch instead of "<num>/merge".

Verified locally by running coverallsJacoco with the production token
plus a CircleCI-shaped env block (the plugin's CircleCI branch is the
best-supported one) — Coveralls returned OK and the build appeared in
the dashboard.

Also re-adds coverallsRequest = file(...) so the request payload is
written to build/coveralls-request.json. The workflow's "Push coverage
to Coveralls" step already cats this file, which makes future
regressions diagnosable from the CI log alone.

Assisted-By: Claude Code

Author: sonus21

.github/workflows/java-ci.yaml

@@ -467,6 +467,8 @@ jobs:
       - name: Push coverage to Coveralls
         env:
           COVERALLS_REPO_TOKEN: ${{ secrets.COVERALLS_REPO_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          BUILD_NUMBER: ${{ github.run_id }}
           CI_BRANCH: ${{ github.head_ref || github.ref_name }}
         run: |
           if [ -z "$COVERALLS_REPO_TOKEN" ]; then

build.gradle

@@ -206,6 +206,7 @@ coverallsJacoco {
     reportSourceSets = publishedProjects.collectMany {
         it.sourceSets.main.allSource.srcDirs
     }
+    coverallsRequest = file("build/coveralls-request.json")
 }
 
 def javaFormatSources = providers.provider {