[BUG][RUBY] client-side-validation throws error with numerical ID validation

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

In the generated code, lines like this are generated for client-side-validation:

pattern = /[0-9]+/
if @api_client.config.client_side_validation && transaction_id !~ pattern
  fail ArgumentError, "invalid value for 'transaction_id' when calling DailyActivityApi.list_activities, must conform to the pattern #{pattern}."
end

The API response for which the client is generated for is returning IDs in numerical form, e.g. 941122920, but this validation is failing with an error like:

undefined method `=~' for 941122920:Integer

openapi-generator version

6.6.0

OpenAPI declaration file content or url

https://www.polar.com/accesslink-api/swagger.yaml

Generation Details

openapi-generator generate -i swagger.yaml -o polar_client -g ruby

Steps to reproduce

In irb:

pattern = /[0-9]+/
transaction_id = 941122920
transaction_id !~ pattern

Related issues/PRs

Suggest a fix

Start with the generated Ruby client-side-validation snippet and reproduce the Integer =~ failure in irb using the command and swagger.yaml URL from the issue. Trace that generated validation back through the Ruby generator, then add coverage for numerical IDs and confirm that client-side validation handles the generated client without raising an Integer method error.