chore(NODE-6037): use metadata for skip logic and remove async from context block

[baileympearson]

Description

What is changing?

• Added an eslint rule for checking mocha describe blocks for async functions
  • Run fix to remove current accidental usages
• Use metadata to skip range tests

Is there new documentation needed for these changes?

No.

What is the motivation for this change?

• Async functions in context/describe blocks are incorrect usage of the test framework. We suspect this lead to a problem with mocha exiting silently on latest sharded clusters, that is no longer happening after this change.

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