Enable async_update for entities in NWS

[MatthewFlamm]

Proposed change

This PR enables async_update which allows users to run manual updates as suggested in this comment. The Debouncer cooldown time is set to 60s to avoid too many updates by users.

I removed the unused config schema which is unneeded and was missed in the conversation to config flow.

PARALLEL_UPDATES is also set, which I think brings this integration up to Platinum level on the quality scale.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

I am following [guidance] (https://www.weather.gov/disclaimer) to limit API calls to no more than once a minute.

• This PR fixes or closes issue: fixes #
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io

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

• The manifest file has all fields filled out correctly.
  Updated and included derived files by running: python3 -m script.hassfest.
• New or updated dependencies have been added to requirements_all.txt.
  Updated by running python3 -m script.gen_requirements_all.
• Untested files have been added to .coveragerc.

The integration reached or maintains the following Integration Quality Scale:

• No score or internal
• 🥈 Silver
• 🥇 Gold
• 🏆 Platinum

[MatthewFlamm]

Having trouble testing that the Debouncer is working the way I think it does, so marked as draft.

[MatthewFlamm]

Figured it out, it wasnt worth trying to test the actual Debouncer behavior. It just didn't work as I expected at first.

[bdraco]

Looks good, tested and working as expected.