MAINTENANCE: Automated closing of pull requests.

This commit exists to close the following pull requests on Github:

Closes #1767 (close requested by 'andrewor14')
Closes #6952 (close requested by 'andrewor14')
Closes #7051 (close requested by 'andrewor14')
Closes #5357 (close requested by 'marmbrus')
Closes #5233 (close requested by 'andrewor14')
Closes #6930 (close requested by 'JoshRosen')
Closes #5502 (close requested by 'andrewor14')
Closes #6778 (close requested by 'andrewor14')
Closes #7006 (close requested by 'andrewor14')