gitlab and github shortcodes use deprecated getJSON function

Description of the problem

v0.135.0 now hard fails on uses of getJSON. our gitlab and github shortcodes each use this. Fix it.

Steps to reproduce it

run hugo

1. Visit '...'
2. Click on '...'
3. Scroll to '...'
4. ...

Expected behavior

site is generated

Behavior detected

errors logged because we're using getJSON