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` (reads from  `required_ruby_version` on Rubocop 1.61.0)
  - [ ] 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”`)

To establish consistency, the `required_ruby_version`is set to 3.0. If you think that another version is a better fit, please make the applicable changes.

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

Author: george-ma

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ["3.2"]
+        ruby: ["3.0", "3.1", "3.2", "3.3"]
     steps:
     - name: Check out code
       uses: actions/checkout@v4

.gitignore

@@ -3,7 +3,6 @@
 .bundle
 .config
 .yardoc
-Gemfile.lock
 InstalledFiles
 _yardoc
 coverage

.ruby-version

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

Gemfile.lock

@@ -0,0 +1,94 @@
+PATH
+  remote: .
+  specs:
+    activerecord-rescue_from_duplicate (0.2.6)
+      activerecord (>= 7)
+
+GEM
+  remote: https://rubygems.org/
+  specs:
+    activemodel (7.1.3.2)
+      activesupport (= 7.1.3.2)
+    activerecord (7.1.3.2)
+      activemodel (= 7.1.3.2)
+      activesupport (= 7.1.3.2)
+      timeout (>= 0.4.0)
+    activesupport (7.1.3.2)
+      base64
+      bigdecimal
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      connection_pool (>= 2.2.5)
+      drb
+      i18n (>= 1.6, < 2)
+      minitest (>= 5.1)
+      mutex_m
+      tzinfo (~> 2.0)
+    base64 (0.2.0)
+    bigdecimal (3.1.7)
+    coderay (1.1.3)
+    concurrent-ruby (1.2.3)
+    connection_pool (2.4.1)
+    diff-lcs (1.5.1)
+    docile (1.4.0)
+    drb (2.2.1)
+    i18n (1.14.4)
+      concurrent-ruby (~> 1.0)
+    method_source (1.0.0)
+    minitest (5.22.3)
+    mutex_m (0.2.0)
+    mysql2 (0.5.6)
+    pg (1.5.6)
+    pry (0.14.2)
+      coderay (~> 1.1)
+      method_source (~> 1.0)
+    rake (13.2.0)
+    rspec (3.13.0)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.0)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.1)
+    simplecov (0.22.0)
+      docile (~> 1.1)
+      simplecov-html (~> 0.11)
+      simplecov_json_formatter (~> 0.1)
+    simplecov-html (0.12.3)
+    simplecov_json_formatter (0.1.4)
+    sqlite3 (1.7.3-aarch64-linux)
+    sqlite3 (1.7.3-arm-linux)
+    sqlite3 (1.7.3-arm64-darwin)
+    sqlite3 (1.7.3-x86-linux)
+    sqlite3 (1.7.3-x86_64-darwin)
+    sqlite3 (1.7.3-x86_64-linux)
+    timeout (0.4.1)
+    tzinfo (2.0.6)
+      concurrent-ruby (~> 1.0)
+
+PLATFORMS
+  aarch64-linux
+  arm-linux
+  arm64-darwin
+  x86-linux
+  x86_64-darwin
+  x86_64-linux
+
+DEPENDENCIES
+  activerecord-rescue_from_duplicate!
+  bundler
+  mysql2
+  pg
+  pry
+  rake
+  rspec
+  simplecov
+  sqlite3
+
+BUNDLED WITH
+   2.5.3

activerecord-rescue_from_duplicate.gemspec

@@ -13,6 +13,8 @@ Gem::Specification.new do |spec|
   spec.homepage      = "https://github.com/Shopify/activerecord-rescue_from_duplicate"
   spec.license       = "MIT"
 
+  spec.required_ruby_version = ">= 3.0"
+
   spec.files         = `git ls-files`.split($/)
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})