PYTHON-5449 & PYTHON-5571 [v4.15] Do not attach invalid document in exception message and fix memory leak#2577

blink1073 wants to merge 2 commits intomongodb:v4.15mongodb/mongo-python-driver:v4.15from

blink1073:cherry-pick-v4.15-52400e11a1ac69bcc89dfe5a034df00a4a7f690cblink1073/mongo-python-driver:cherry-pick-v4.15-52400e11a1ac69bcc89dfe5a034df00a4a7f690cCopy head branch name to clipboard