Requests with missing `required` `format: date-time` parameters are not rejected

[WillMorrison]

The generated runtime code binds a missing required query parameter with format: date-time as the zero time.Time object instead of rejecting the request. This bug is related to the format: date-time, as requests missing required string query parameters without a format are correctly rejected.

Reproduction demo, including a comparison with oapi-codegen v2 behaviour, can be found in https://github.com/WillMorrison/vigilant-octo-potato
I have only tried the std-http server type and query parameters.