feat(NODE-6884): remove support for 4.0

[durran]

Description

Drops support for server 4.0

What is changing?

• Bumps min wire version to 8
• Bumps min server version to 4.2
• Removes tests specifically around versions < 4.2
• Updates spec tests to remove or update in line with test(DRIVERS-3034): remove/update 4.0 related tests specifications#1796

Is there new documentation needed for these changes?

None

What is the motivation for this change?

NODE-6884
DRIVERS-3187

Release Highlight

Support for MongoDB 4.0 is removed

When the driver connects to a MongoDB server of version 4.0 or less, it will now throw an error.

Double check the following

• Ran npm run check:lint script
• Self-review completed using the steps outlined here
• PR title follows the correct format: type(NODE-xxxx)[!]: description
  • Example: feat(NODE-1234)!: rewriting everything in coffeescript
• Changes are covered by tests
• New TODOs have a related JIRA ticket

[baileympearson]

No major comments. I'd like to see mongodb/specifications#1796 resolved before we merge this PR though, so we can make sure the changes to the pre-6.0 SDAM tests are the same as the spec's.