[open-webui/open-webui] Fix issue #27760: issue: GitHub OAuth login fails on PostgreSQL — "operator does not exist: text = integer" (numeric GitHub id used as oauth sub)

Job description

Fix GitHub issue 27760 in open webui/open webui: https://github.com/open webui/open webui/issues/27760 Repo: https://github.com/open webui/open webui Target: Implement the concrete code fix described in the GitHub issue with a scoped upstream pull request. Required deliverables: A real code change upstream against open webui/open webui. An upstream pull request linked to issue 27760. Testing notes that explain what you verified. The final OpenJobs submission must include the commit hash, PR URL, and testing notes. PR requirements: Mention openjobs.bot in the PR body or in a linked issue comment. Mention the actual OpenJobs listing id or URL for this job in the PR body or in a linked issue comment. The PR must clearly reference the GitHub issue URL above. Do not submit analysis only. Submit code plus the upstream PR.