No GitHub repositories found when using SSH aliases

**Describe the bug**
When using SSH config aliases (see the example below), the GitHub Actions extension returns the error message "No GitHub repositories found". SSH aliases are often used when a user has multiple GitHub accounts that have separate SSH keys.

This only occurs when using an alias that does not include `github.com` in the alias name. If I were to change the alias name to, for example, `personal.github.com`, as well as the remote, then the extension works without issue.

**To Reproduce**
Steps to reproduce the behavior:
1. Create an alias in your SSH config file (e.g., ~/.ssh/config) with any name that does not include `github.com`.
2. Switch your origin remote to use the alias (e.g., git@alias:username/repo.git)
3. Reload VSCode
4. Switch to the GitHub Actions extension and see "No GitHub repositories found"
5. Switch your origin remote back to a standard "github.com" alias
6. Reload VSCode
7. Switch to the GitHub Actions extension and see standard functionality.

**Expected behavior**
GitHub Actions would work regardless of the SSH config alias.

**Extension Version**
`v0.27.2`

**Additional context**
Logs from the extension when using a non-github.com alias:

```
Activating GitHub Actions extension...
Error getting GitHub context
Invalid URL
TypeError: Invalid URL
at new URL (node:internal/url:818:25)
at /Users/josephgruber/.vscode/extensions/github.vscode-github-actions-0.27.2/dist/extension-node.js:1:1158030
at async Promise.all (index 0)
at async /Users/josephgruber/.vscode/extensions/github.vscode-github-actions-0.27.2/dist/extension-node.js:1:1157669
at async De (/Users/josephgruber/.vscode/extensions/github.vscode-github-actions-0.27.2/dist/extension-node.js:1:1157518)
at async os (/Users/josephgruber/.vscode/extensions/github.vscode-github-actions-0.27.2/dist/extension-node.js:1:1339675)
at async Lb.n (file:///Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/api/node/extensionHostProcess.js:112:13382)
at async Lb.m (file:///Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/api/node/extensionHostProcess.js:112:13345)
at async Lb.l (file:///Applications/Visual%20Studio%20Code.app/Contents/Resources/app/out/vs/workbench/api/node/extensionHostProcess.js:112:12801)
```

Start by tracing extension activation and the GitHub context lookup that fails with Invalid URL when the remote uses a non-github.com SSH alias. Reproduce with the SSH configuration and remote forms described in the issue, then verify that repository discovery works for both aliased and standard GitHub remotes.

Written by the indexing model from the issue text.