Sort (and deduplicate) type aliases

[danielrbradley]

• Use a set to ensure we don't add duplicate aliases.
• Render the aliases ordered.

This just affects explicit versions, moving the default version from the first alias to the last in the list.

This will allow us to add additional sources of aliases (from the previous major version) without causing duplicates.

[github-actions]

Does the PR have any schema changes?

Looking good! No breaking changes found.
No new resources/functions.

[codecov]

Codecov Report

Attention: Patch coverage is 92.85714% with 1 line in your changes missing coverage. Please review.

Project coverage is 57.06%. Comparing base (0a344cb) to head (93c9cb7).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
provider/pkg/gen/schema.go	92.85%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3902   +/-   ##
=======================================
  Coverage   57.06%   57.06%           
=======================================
  Files          78       78           
  Lines       12469    12470    +1     
=======================================
+ Hits         7115     7116    +1     
  Misses       4807     4807           
  Partials      547      547           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.