Bug: Pagy::I18n.locale should work with Symbol values

### 👀 Before submitting... - [x] I upgraded to pagy version 43.2.4 - [x] I asked [Pagy AI](https://gurubase.io/g/pagy) (Good starting point for further investigation). - [x] I searched through the [Documentation](https://ddnexus.github.io/pagy/), [Issues](https://github.com/ddnexus/pagy/issues), and [Q&A](https://github.com/ddnexus/pagy/discussions/categories/q-a) ### 🧐 REQUIREMENTS - [x] I am providing a VALID code file that confirms the bug - [x] I am NOT posting any of the USELESS THINGS listed above - [x] I am aware that this issue will be automatically closed if the code file is missing or INVALID ### 💬 Description ## Problem When setting `Pagy::I18n.locale` with a symbol (e.g., `:en`), an error occurs when using `@pagy.info_tag`. The error message is: ``` NoMethodError: undefined method '[]' for nil ``` ## Environment - Pagy version: 43.2.4 - Rails version: 8.1.2 - Ruby version: 3.4.8 ## Steps to Reproduce 1. Configure Rails with a symbol locale: ```ruby # config/application.rb config.i18n.default_locale = :en ``` 2. Set `Pagy::I18n.locale` using `I18n.default_locale`: ```ruby # app/controllers/application_controller.rb include Pagy::Method before_action { Pagy::I18n.locale = I18n.default_locale } ``` 3. Use `@pagy.info_tag` in a view: ```erb <%== @pagy.info_tag %> ``` 4. The error occurs: `NoMethodError: undefined method '[]' for nil` In most cases, `I18n.default_locale` in Rails is typically represented as a symbol (e.g., `:en`). While the [Pagy I18n Documentation](https://ddnexus.github.io/pagy/resources/i18n/#configuration-for-multilingual-applications) mentions this configuration for "multiple locales", this issue also affects single-locale applications. In applications that support a single language, rather than receiving the locale from parameters like `params[:locale]`, implementations tend to reference the default value of `I18n.default_locale`. Therefore, I expect that symbols are passed to `Pagy::I18n.locale` in many cases as a natural flow of the code. The documentation shows setting `Pagy::I18n.locale = params[:locale]`, which typically returns a string, but doesn't mention the incompatibility with symbol locales often used in Rails applications. ## Expected Behavior `Pagy::I18n.locale` should accept both String and Symbol values, automatically converting symbols to strings internally. ## Actual Behavior `Pagy::I18n.locale` only accepts String values. When a Symbol is passed, the locale dictionary lookup fails, resulting in `nil` being returned, which then causes `undefined method '[]' for nil` errors when trying to access translation keys. ## Workaround Currently, we need to explicitly convert the symbol to a string: ```ruby before_action { Pagy::I18n.locale = I18n.default_locale.to_s } ``` However, this requires an explicit `to_s` conversion and is inconvenient when `I18n.default_locale` (which returns a symbol) is used directly. ## Proposed Solution Modify the `locale=` method in `Pagy::I18n` to accept both String and Symbol values, converting symbols to strings internally. https://github.com/ddnexus/pagy/blob/43.2.4/gem/lib/pagy/modules/i18n/i18n.rb#L15-L17 --- Please note that my understanding of the Pagy implementation and documentation may not be entirely accurate. If there are any misunderstandings in this issue, I would appreciate your guidance.