Refactor GitHubSocialAuth to use global requests instead of session

[Macktireh]

No description provided.

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
src/simplesocialauthlib
__init__.py	0	0	100%
abstract.py	37	3	92%	73, 89, 105
exceptions.py	14	0	100%
types.py	15	0	100%
utils.py	24	14	42%	26–39
src/simplesocialauthlib/providers
__init__.py	21	11	48%	7–8, 14–15, 19–25, 29–30, 34–35
github.py	42	13	69%	58–75, 80–88
google.py	50	16	68%	78–92, 97–123
TOTAL	203	57	72%

Tests	Skipped	Failures	Errors	Time
11	0 💤	0 ❌	0 🔥	1.104s ⏱️