This is already prevented by the API, but this will make the error
message cleaner and easier to understand for the user.
Example of old error message:
```
$ gh cs edit -c cwndrws-redacted -d "some silly name"
error editing codespace: HTTP 422: your codespace has an operation pending: updating to a sku with a different amount of storage; please wait until this operation is complete (https://api.github.com/user/codespaces/cwndrws-redacted)
exit status 1
```
Example of new error message:
```
$ gh cs edit -c cwndrws-redacted -d "some silly name"
error editing codespace: codespace is disabled while it has a pending operation: Changing machine types...
exit status 1
```
gh codespace commands now respect the following environment variables:
- GITHUB_SERVER_URL: typically "https://github.com"
- GITHUB_API_URL: typically "https://api.github.com"
- INTERNAL_VSCS_TARGET_URL: typically "https://online.visualstudio.com"
- GITHUB_TOKEN when CODESPACES is set, even if the host connecting to isn't "github.com".
This set of changes ensures that `gh codespace` commands automatically connect to the right API endpoints when gh is used within a codespace.
Co-authored-by: Mislav Marohnić <mislav@github.com>
