Add git repo as output for build tasks

This is required for exporting the Gradle Build Scan URL to
notifications.

See gh-22490

ci/tasks/build-project.yml

@@ -4,6 +4,7 @@ inputs:
 - name: git-repo
 outputs:
 - name: distribution-repository
+- name: git-repo
 caches:
 - path: gradle
 params:

ci/tasks/check-project.yml

@@ -4,6 +4,7 @@ inputs:
 - name: git-repo
 outputs:
 - name: distribution-repository
+- name: git-repo
 caches:
 - path: gradle
 params: