Update with merge commit feature not working

[NPorcu-BHS]

Maybe related to or caused by issue #8231

The feature is still working with v0.126.0 and stopped working somewhere between v0.126.0 and v0.128.0 and is still broken in the latest prerelease v0.129.2026022604

• Extension version: v0.129.2026022604 (pre-release), v0.128.0
• VSCode Version: 1.109.5 (system setup)
• OS: Windows 11
• GitHub Product (GitHub.com/GitHub Enterprise version x.x.x): GitHub Enterprise Server 3.17.7

Steps to Reproduce:

1. Checkout branch with open pull request
2. Base branch should contain new changes
3. Open pull request extension web view ("This branch is out-of-date with base branch." is visible)
4. Click "Update with merge commit" button
5. Loading bar appears for a blink of a second
6. Nothing happens

Logs after button click:
2026-02-27 11:03:57.234 [error] [GitHubRepository] Updating branch using GraphQL UpdatePullRequestBranch mutation failed: Invariant Violation: Invariant Violation: 9 (see https://github.com/apollographql/invariant-packages)
2026-02-27 11:03:59.584 [info] [FolderRepositoryManager+0] Using in-memory cached assignable users.
2026-02-27 11:03:59.821 [info] [Authentication] Creating hub for enterprise
2026-02-27 11:03:59.821 [info] [Authentication] Enterprise server authority [REDACTED GH ENTERPRISE URL]
2026-02-27 11:04:00.016 [info] [FolderRepositoryManager+0] Found GitHub remote for folder [REDACTED FOLDER STRUCTURE]
2026-02-27 11:04:00.017 [info] [FolderRepositoryManager+0] Using in-memory cached mentionable users.
2026-02-27 11:04:00.017 [info] [FolderRepositoryManager+0] Using in-memory cached assignable users.

[alexr00]

We switched to use GitHub's graphQL API for the update, rather than git API. Seems like for GitHub enterprise we should keep using the old git API approach. Thanks for reporting this!