Centralize Ruby Version to .ruby-version

The `.ruby-version` file is the ecosystem standard for defining a Ruby version.  This PR adds the `.ruby-version` file, ensures a `required_ruby_version` is set, and removes all other references to Ruby in this repository, aligning it with the standard.
> [!IMPORTANT]
> Please verify the following before merging:

Verify that the changes in the PR meets the following requirements or adjust manually to make it compliant:
  - [ ] `.ruby-version` file is present with the correct Ruby version defined
  - [ ] A `required_ruby_version` in your gemspec is set
  - [ ] There is no Ruby version present in the  `dev.yml` Ruby task (before: `- ruby: x.x.x`, after: `- ruby`)
  - [ ] There is no Ruby version/requirement referenced in the `Gemfile` (no lines with `ruby  <some-version>`)
  - [ ] A `Gemfile.lock` is built with the defined Ruby version
  - [ ] The version of Rubocop installed is 1.61.0 or greater
  - [ ] There is no `TargetRubyVersion` defined  in `rubocop.yml`
  - [ ] There is no Ruby argument  present in  `ruby/setup-ruby` Github Actions that do **not**  run on a Ruby matrix (no lines with `ruby-version: “x.x”`)

Please merge this PR if it looks good, this PR will be merged if there isn't any activity after 4 weeks.

.github/workflows/ci.yml

@@ -30,7 +30,6 @@ jobs:
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 3.2
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically
     - name: Rubocop run
       run: |
@@ -48,7 +47,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['3.0', '3.1', '3.2']
+        ruby-version: ['3.0', '3.1', '3.2', '3.3']
 
     steps:
     - uses: actions/checkout@v3

.github/workflows/gem-push.yml

@@ -16,8 +16,6 @@ jobs:
     - uses: actions/checkout@v3
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
-      with:
-        ruby-version: 3.2
 
     - name: Publish to RubyGems
       run: |

.gitignore

@@ -7,4 +7,3 @@
 /spec/reports/
 /tmp/
 .rubocop-https*
-Gemfile.lock

.rubocop.yml

@@ -7,7 +7,6 @@ require:
 
 AllCops:
   NewCops: enable
-  TargetRubyVersion: 3.2
 
 Naming/FileName:
   Exclude:

.ruby-version

@@ -0,0 +1 @@
+3.3.0

dev.yml

@@ -3,7 +3,7 @@
 name: limiter
 
 up:
-  - ruby: 3.2.2
+  - ruby
   - bundler
 
 commands:

limiter.gemspec

@@ -13,7 +13,7 @@ Gem::Specification.new do |spec|
   spec.summary       = "Simple Ruby rate limiting mechanism."
   spec.homepage      = "https://github.com/Shopify/limiter"
   spec.license       = "MIT"
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.6.0")
+  spec.required_ruby_version = Gem::Requirement.new(">= 3.0.0")
 
   if spec.respond_to?(:metadata)
     spec.metadata["allowed_push_host"] = "https://rubygems.org"