Tighten type checking config

[kanongil]

This adds noUncheckedIndexedAccess: true and exactOptionalPropertyTypes: true to the type checking config.

This helps ensure that the defined typings can work for projects like reported here, which use these stricter than strict: true options.

I also updated the peer dependency requirement to v4.4.0+, which is the oldest version that supports these flags.

[kanongil]

The 316d8c1 patch can be omitted, if #1070 is merged. Otherwise, two additional codes need to be added to the list to handle the expect.error() lines in b801fae.

[devinivy]

Looks great, thanks for getting this going 👍