Switch github workflow service back to main (#1458)

Author: ChrisC

server/services/GithubWorkflowService.js

@@ -194,7 +194,7 @@ const createGithubWorkflow = async ({ job, directory, gitSha, atVersion }) => {
       'X-GitHub-Api-Version': '2022-11-28'
     },
     data: JSON.stringify({
-      ref: 'self-hosted',
+      ref: 'main',
       inputs
     }),
     validateStatus: () => true,