Consider enabling jest/unbound-method rule

[ianshade]

It looks like we're missing a rule that adds support for understanding when it's ok to pass an unbound method to expect calls.
Without it there are test files in Sofie Core that need workarounds like this one
More about the rule:
https://github.com/jest-community/eslint-plugin-jest/blob/main/docs/rules/unbound-method.md