Update rspec-its requirement from ~> 1.0 to ~> 2.0

Updates the requirements on [rspec-its](https://github.com/rspec/rspec-its) to permit the latest version.
- [Changelog](https://github.com/rspec/rspec-its/blob/main/Changelog.md)
- [Commits](rspec/rspec-its@v1.0.0...v2.0.0)

---
updated-dependencies:
- dependency-name: rspec-its
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

rspec-json_matchers.gemspec

@@ -32,7 +32,7 @@ Gem::Specification.new do |spec|
 
   spec.add_development_dependency "rake", ">= 10.0", "<= 14.0"
   spec.add_development_dependency "appraisal", "~> 2.0", ">= 2.5.0"
-  spec.add_development_dependency "rspec-its", "~> 1.0"
+  spec.add_development_dependency "rspec-its", "~> 2.0"
   spec.add_development_dependency "simplecov", ">= 0.21"
   spec.add_development_dependency "simplecov-lcov", ">= 0.8"
   spec.add_development_dependency "gem-release", "~> 2.0"