Prevent prereleases from showing up in updater (#4997)

## What type of PR is this? (check all applicable)

- [ ] Refactor
- [ ] Feature
- [X] Bug Fix
- [ ] Optimization
- [ ] Documentation Update
- [ ] Community Node Submission


## Have you discussed this change with the InvokeAI team?
- [X] Yes
- [ ] No, because:

      
## Have you updated all relevant documentation?
- [X] Yes
- [ ] No


## Description

This PR prevents the invokeai update script from offering prereleases.

invokeai/frontend/install/invokeai_update.py

@@ -91,7 +91,7 @@ def get_extras():
 
 
 def main():
-    versions = get_versions()
+    versions = [x for x in get_versions() if not (x['draft'] or x['prerelease'])]
     if invokeai_is_running():
         print(":exclamation: [bold red]Please terminate all running instances of InvokeAI before updating.[/red bold]")
         input("Press any key to continue...")