Align proper Slack channels per recent Docker Hub request (#3967)

More context can be found in the related Slack thread below. Apologies again for @JJediny.

https://gsa-tts.slack.com/archives/C039MHHF8/p1725908739784519?thread_ts=1725630358.508639&cid=C039MHHF8

Co-authored-by: John Jediny <[email protected]>

Author: aj-stein-gsa

pages/tools/docker-hub.md

@@ -12,7 +12,7 @@ use with [Docker](https://www.docker.com/) and other container technologies.
 ## How do I get access to Docker Hub?
 
 You may use your personal Docker Hub account for work. Ask
-{% slack_channel "infrastructure" %} for access to the
+{% slack_channel "admins-docker" %} for access to the
 [TTS-wide account](https://hub.docker.com/orgs/gsatts).
 
 ## For admins