Tekton Pipelines: Git resolver API mode leaks system-configured API token to user-controlled serverURL

Tekton Pipelines project provides k8s-style resources for declaring CI/CD-style pipelines. Starting in version 1.0.0 and prior to versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1, the Tekton Pipelines git resolver in API mode sends the system-configured Git API token to a user-controlled serverURL when the user omits the token parameter. A tenant with TaskRun or PipelineRun create permission can exfiltrate the shared API token (GitHub PAT, GitLab token, etc.) by pointing serverURL to an attacker-controlled endpoint. Versions 1.0.2, 1.3.4, 1.6.2, 1.9.3, and 1.11.1 fix the issue.