Disallow getting logs from codespaces with pending ops

Since the API already disallows this, this pretty much just cleans up
the error reporting to the user.

Example of old error:

```
$ gh cs logs -c cwndrws-redacted
Starting codespace ⣽connecting to codespace: error starting 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/start)
exit status 1

```

Example of new error:

```
$ gh cs logs -c cwndrws-redacted
codespace is disabled while it has a pending operation: Changing machine types...
exit status 1
```

pkg/cmd/codespace/logs.go

@@ -41,6 +41,13 @@ func (a *App) Logs(ctx context.Context, codespaceName string, follow bool) (err
 		return fmt.Errorf("get or choose codespace: %w", err)
 	}
 
+	if codespace.PendingOperation {
+		return fmt.Errorf(
+			"codespace is disabled while it has a pending operation: %s",
+			codespace.PendingOperationDisabledReason,
+		)
+	}
+
 	authkeys := make(chan error, 1)
 	go func() {
 		authkeys <- checkAuthorizedKeys(ctx, a.apiClient)