fix(NODE-6241): allow Binary as local kms provider key for auto encryption

[baileympearson]

Description

What is changing?

This fixes the compile_ts task in mongosh's CI: https://evergreen.mongodb.com/task/mongosh_linux_unit_compile_ts_667efa29aa31110007944584_24_06_28_18_00_09/0?redirect_spruce_users=true.

Is there new documentation needed for these changes?

What is the motivation for this change?

Release Highlight

The LocalKMSProviderConfiguration's key property accepts Binary for auto encryption

In #4160 we fixed a type issue where a local KMS provider at runtime accepted a BSON Binary instance but the Typescript inaccurately only permitted Buffer and string. The same change has now been applied to AutoEncryptionOptions.

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