[2.7] bpo-33767: Fix improper use of SystemError by mmap.mmap objects (GH-7381) (GH-7432)

Raise TypeError instead of SystemError for unsupported operations.
(cherry picked from commit e9e397605789b2a67b67558fbbe756b7b88934f5)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>
3 files changed