chore: remove find_github_backup_info.py (#9307)

Author: jennifer-richards

ietf/doc/management/commands/find_github_backup_info.py

@@ -38,7 +38,6 @@ drf-spectacular>=0.27
 drf-standardized-errors[openapi] >= 0.14
 types-docutils>=0.18.1
 factory-boy>=3.3
-github3.py>=3.2.0
 gunicorn>=20.1.0
 hashids>=1.3.1
 html2text>=2020.1.16    # Used only to clean comment field of secr/sreq