fix(autofix): Only call the repo check if it's github

[jennmueng]

Don't call the repo access check endpoint if it's not a github provider.

[roaga]

ty

[codecov]

Codecov Report

Attention: Patch coverage is 33.33333% with 2 lines in your changes missing coverage. Please review.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
.../sentry/api/endpoints/group_autofix_setup_check.py	33.33%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##           master   #80847   +/-   ##
=======================================
  Coverage   78.41%   78.41%           
=======================================
  Files        7209     7209           
  Lines      319622   319625    +3     
  Branches    44006    44007    +1     
=======================================
+ Hits       250642   250647    +5     
  Misses      62594    62594           
+ Partials     6386     6384    -2