docs: remove beta info from VS Code README

Description

Removes the beta-related language in prep for the 2023-12-21 GA.

This merge request uses GitLab repo: change Code Suggestion to GA (gitlab!139770 - merged) as a blocker to ensure we do not merge changes to the groupeditor extensions repos until after the changes to the gitlab repo are merged.

Related items

• Related to Remove Beta labeling for Code Suggestions settings (gitlab-org/editor-extensions&19 - closed)
• Related to Remove GitLab SaaS Beta label from documentation (gitlab#435271 - closed)

How has this been tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation
• Chore (Related to CI or Packaging to platforms)
• Test gap