Fix US states check (fixes #7015)

[fabaff]

Description:

For the US there are STATES while for other countries PROVINCES is used.

Related issue (if applicable): fixes #7015

Example entry for configuration.yaml (if applicable):

binary_sensor:
  - platform: workday
    country: US
    province: WA

Checklist:

If the code communicates with devices, web services, or third-party tools:

• [] Local tests with tox run successfully. Your PR cannot be merged unless tests pass

[mention-bot]

@fabaff, thanks for your PR! By analyzing the history of the files in this pull request, we identified @BastianPoe to be a potential reviewer.

[drkp]

This isn't enough, it looks like you also need to use state= instead of prov= (line 76) in order to get holidays to return the state-specific info. With prov, it just ignores the value (ugh!):

>>> len(holidays.US(years=2017))
12
>>> len(holidays.US(years=2017, state="CA"))
14
>>> len(holidays.US(years=2017, prov="CA"))
12

[balloob]

Cherry picked for 0.42.3