Merge release/2.3 into master

[mongodb-drivers-pr-bot]

Merge new changes from release/2.3 into master.

Commits

• GODRIVER-3648 Make server selection block on topology updates. (GODRIVER-3648 Make server selection block on topology updates. #2211): a05e146

Resolving conflicts

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

git merge master -m "Resolve conflicts in master"

Ignoring changes

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

git reset --hard master
git merge --strategy=ours release/2.3 -m "Ignore changes from release/2.3"

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

[matthewdale]

Looks good! 👍