[grid] Doing `.countDown()` when the right event has been listened to

Avoiding running tests for changed referrer header behaviour on firefox

Add missing target to Rakefile

Amend java release targets

Adding support for CDP version 87 in .NET

[py] Bump version to 4a6

Updating .NET tests

[java] Switching default client implementation from okhttp to netty

Adjusting Rakefile for next release

Prevent chromium driver info from being considered a class that be ne…

…wed up