Fix supporting encrypted configuration with integer keys about rails

[rafaelfranca]

When does an integer as credential name makes sense?

[fabianof]

Thanks for asking, Rafael.

Following is a real use case from one of my applications (using fake credentials), in which I have a "year => spreadsheet ID" mapping.

google:
  credentials: config/credentials/google/development.json
  spreadsheet_id:
    2021: 81ab723369a5f16cb68d22f67089b4754befbb32a91b
    2022: ede01aa536d886affa5a4795ff76766413f1a5b062f0
    2023: e0b894384abdcbfb7549ab23907435668f7b48c7ff12
    2024: a59545b56a896e821dcf8b8e6315a68c412bbbff531c

With that in place I've been used to do this for a long time:

Rails.application.credentials[:google][:spreadsheet_id][month.year]

Without accepting integer keys, I have to worry about parsing month.year to string (for example), which is not the behavior I would expect from a hash.