[Ruby] Unify tests with raw_records and each_raw_record

[otegami]

Describe the enhancement requested

Currently, we are using the same test cases for both raw_records and each_raw_record.
I'd like to unify these test cases to facilitate testing. You can see the related test codes here.

• raw_records: https://github.com/apache/arrow/tree/main/ruby/red-arrow/test/raw-records
• each_raw_record: https://github.com/apache/arrow/tree/main/ruby/red-arrow/test/each-raw-record

Component(s)

Ruby

[otegami]

I will fix it!

[otegami]

take