Revert "[MM-37013] Async job to fix CRT channel unreads (#18340)" (#19319)

This reverts commit 0da249c651.

imports/placeholder.go

@@ -39,7 +39,4 @@ import (
 
 	// This is a placeholder so this package can be imported in Team Edition when it will be otherwise empty.
 	_ "github.com/mattermost/mattermost-server/v6/jobs/extract_content"
-
-	// This is a placeholder so this package can be imported in Team Edition when it will be otherwise empty.
-	_ "github.com/mattermost/mattermost-server/v6/jobs/fix_crt_channel_unreads"
 )