Disable Local Server flow for REH (microsoft#191930)

Because spinning up ports on the remote won't always work. Instead, we have the trusty device code flow.

Fixes microsoft#191866
Fixes microsoft#191867

Author: TylerLeonhardt

extensions/github-authentication/src/flows.ts

@@ -200,7 +200,9 @@ const allFlows: IFlow[] = [
 			// other flows that work well.
 			supportsGitHubEnterpriseServer: false,
 			supportsHostedGitHubEnterprise: true,
-			supportsRemoteExtensionHost: true,
+			// Opening a port on the remote side can't be open in the browser on
+			// the client side so this flow won't work in remote extension hosts
+			supportsRemoteExtensionHost: false,
 			// Web worker can't open a port to listen for the redirect
 			supportsWebWorkerExtensionHost: false,
 			// exchanging a code for a token requires a client secret