switch from dockerhub to ghcr, improve docker caching (#2695)

## Description:

Switch to GHCR for faster pulls/pushes and increased rate limits
Use cache-builder driver for better caching, so npm ci is cached if
dependencies don't change.



## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

evan

example.env

@@ -2,9 +2,9 @@
 SSH_KEY=~/.ssh/your-ssh-key
 
 # Docker Configuration
-DOCKER_USERNAME=username
-DOCKER_REPO=your-repo-name
-DOCKER_TOKEN=your_docker_token_here
+GHCR_USERNAME=username
+GHCR_REPO=your-repo-name
+GHCR_TOKEN=your_docker_token_here
 
 # Admin credentials
 ADMIN_TOKEN=your_admin_token_here