Merge 4.3 into 4.4

[mongodb-php-bot]

Merge new changes from 4.3 into 4.4.

Commits

• Improve error message for invalid configuration (Improve error message for invalid configuration #2975): 7b8f0a1
• Automatically label docs PR (Automatically label docs PR #2972): 7545177

Resolving conflicts

To resolve any conflicts, check out the temporary branch and run the following command:

git merge 4.4

Ignoring changes

To ignore from the remote branch, first reset the temporary branch to 4.4 and manually merge using the `ours` merge strategy:

git reset --hard 4.4
git merge --strategy=ours 4.3

Then, push the temporary branch to upate the pull request.