Pull Request explorer pane is not shown when it is hidden and opening PR from a URL

[dmitrivMS]

Testing microsoft/vscode#274805

1. Open vscode repo in VS Code
2. Open a PR, make sure "GitHub Pull Request" pane is visible
3. Right-click on the sidebar, and hide the "GitHub Pull Request" pane
4. Now open a PR from URL in the browser again: vscode-insiders://github.vscode-pull-request-github/checkout-pull-request?%7B%22owner%22%3A%22microsoft%22%2C%22repo%22%3A%22vscode%22%2C%22pullRequestNumber%22%3A273860%7D

Actual Result
Nothing happens (output log shows success!)

Expected Result
The GitHub Pull Request pane to be shown and visible to the user.

Output Log

2025-11-04 14:15:28.451 [info] [PullRequestTree] Creating file and commit nodes for PR microsoft/vscode#273860
2025-11-04 14:15:28.453 [info] [PullRequestTree] Getting children for Files node
2025-11-04 14:15:28.453 [info] [PullRequestTree] Got all children for Files node
2025-11-04 14:16:06.611 [info] [Review+0] Switch to Pull Request microsoft/vscode#273860 - start
2025-11-04 14:16:08.513 [info] [Review+0] Switch to Pull Request microsoft/vscode#273860 - done
2025-11-04 14:16:08.513 [info] [Review+0] Validate state in progress
2025-11-04 14:16:08.514 [info] [Review+0] Validating state...
2025-11-04 14:16:08.520 [info] [FolderRepositoryManager+0] Found GitHub remote for folder c:\Users\dmitriv\repos\vscode
2025-11-04 14:16:08.520 [info] [FolderRepositoryManager+0] Trying to use globalState for mentionableUsers.
2025-11-04 14:16:08.521 [info] [FolderRepositoryManager+0] Using in-memory cached assignable users.
2025-11-04 14:16:08.551 [info] [FolderRepositoryManager+0] Using globalState mentionableUsers for 1.
2025-11-04 14:16:08.600 [info] [Review+0] Found matching pull request metadata for current branch dev/dmitriv/glob-2. Repo: microsoft/vscode PR: 273860
2025-11-04 14:16:08.600 [info] [Review+0] current branch dev/dmitriv/glob-2 is associated with pull request microsoft/vscode#273860
2025-11-04 14:16:08.600 [info] [Review+0] Resolving pull request
2025-11-04 14:16:10.163 [info] [GitHubRepository+0] Fetch branch main - enter
2025-11-04 14:16:10.519 [info] [GitHubRepository+0] Fetch branch main - done: true
2025-11-04 14:16:10.519 [info] [Review+0] Resolved PR microsoft/vscode#273860, state is OPEN