Update dotenv requirement from ~> 2.8.0 to ~> 3.0.0

Updates the requirements on [dotenv](https://github.com/bkeepers/dotenv) to permit the latest version.
- [Release notes](https://github.com/bkeepers/dotenv/releases)
- [Changelog](https://github.com/bkeepers/dotenv/blob/main/Changelog.md)
- [Commits](bkeepers/dotenv@v2.8.0...v3.0.0)

---
updated-dependencies:
- dependency-name: dotenv
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

blinka_reporter.gemspec

@@ -31,7 +31,7 @@ Gem::Specification.new do |gem|
  gem.require_path = ["lib"]
 
  gem.add_dependency("ox", "~> 2")
- gem.add_development_dependency("dotenv", "~> 2.8.0")
+ gem.add_development_dependency("dotenv", "~> 3.0.0")
  gem.add_development_dependency("minitest", "~> 5.0")
  gem.add_development_dependency("mocha", "~> 2.0")
  gem.add_development_dependency("rake", "~> 13")