Pull docker tunnel from GHCR instead of Docker Hub

They're tightening rate limits, and strongly implying it'll cause
problems. It's a tiny image with a one-off pull, but pulling from our
GHCR repo (seemingly no rate limit, for now) makes a lot more sense.

Author: pimterry

src/interceptors/docker/docker-tunnel-proxy.ts

@@ -8,7 +8,7 @@ import { isDockerAvailable } from './docker-interception-services';
 import { logError } from '../../error-tracking';
 import { waitForDockerStream } from './docker-utils';
 
-const DOCKER_TUNNEL_IMAGE = "httptoolkit/docker-socks-tunnel:v1.2.0";
+const DOCKER_TUNNEL_IMAGE = "ghcr.io/httptoolkit/docker-socks-tunnel:v1.2.0";
 const DOCKER_TUNNEL_LABEL = "tech.httptoolkit.docker.tunnel";
 
 const getDockerTunnelContainerName = (proxyPort: number) =>