Make NatsJwt Static

[rickdotnet]

As noted in #42, NatsJwt could provide simpler access if made static. I'm currently reusing a singleton instance, but making it static would eliminate the need for this

Unless there are reasons against it, this PR marks NatsJwt as static.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.64%. Comparing base (8aaac6a) to head (f35f164).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #43   +/-   ##
=======================================
  Coverage   80.64%   80.64%           
=======================================
  Files          51       51           
  Lines         966      966           
  Branches       92       92           
=======================================
  Hits          779      779           
  Misses        160      160           
  Partials       27       27           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[Copilot]

Pull Request Overview

This PR converts the NatsJwt class into a static class to simplify its usage by removing the need for instantiation. Key changes include refactoring tests to call static methods, updating PublicAPI definitions, and modifying the NatsJwt implementation accordingly.

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/NATS.Jwt.Tests/ValidationTests.cs	Removed instance creation and updated method calls to the static NatsJwt API.
tests/NATS.Jwt.Tests/NatsJwtTests.cs	Updated all tests to reference static methods instead of instance methods.
tests/NATS.Jwt.Tests/ConnectTests.cs	Refactored JWT generation tests to use the new static method calls.
tests/NATS.Jwt.TestNativeAot/Program.cs	Converted instance usage to static calls in the native AOT test sample.
src/NATS.Jwt/PublicAPI.Unshipped.txt	Updated public API documentation to reflect the change from instance methods to static methods.
src/NATS.Jwt/NatsJwt.cs	Converted the NatsJwt class and all its methods to static, removing the need to instantiate the class.

Comments suppressed due to low confidence (2)

src/NATS.Jwt/NatsJwt.cs:23

• Ensure that converting NatsJwt into a static class does not inadvertently remove any required state management or configuration capability that was previously embedded in instance behavior.

public static class NatsJwt

src/NATS.Jwt/PublicAPI.Unshipped.txt:386

• Update the public API documentation and release notes to clearly indicate that the NatsJwt APIs are now static, and that instance methods have been removed as part of this breaking change.

NATS.Jwt.Models.TimeRange.Start.set -> void

[mtmk]

LGTM thanks @rickdotnet it makes sense. iirc there was a suggestion for static before as well