Add support of SECRET_KEY_BASE_DUMMY env variable

[OlegChuev]

Is your feature request related to a problem? Please describe.

The main idea is to add support for the Rails built-in environment variable SECRET_KEY_BASE_DUMMY. If a user has added this variable, we skip any kind of validations for required attributes. This could be useful for executing bundle exec rails assets:precompile in CI/CD pipelines.

Describe the solution you'd like

As far as I can see (I'm not very familiar with the gem's codebase), we could add an additional condition to the validate_required_attributes method:

    def validate_required_attributes!
      self.class.required_attributes.select do |name|
        val = values.dig(*name.to_s.split(".").map(&:to_sym))
        val.nil? || (val.is_a?(String) && val.empty?)
      end.then do |missing|
        next if missing.empty? || ENV['SECRET_KEY_BASE_DUMMY'].present? <- Add validation here
        raise_validation_error "The following config parameters for `#{self.class.name}(config_name: #{self.class.config_name})` are missing or empty: #{missing.join(", ")}"
      end
    end

Describe alternatives you've considered

Additional context

[palkan]

Yeah, makes sense.

The way we should do that is as follows:

• Add a global setting to disable validations, smth like: Anyway::Settings.suppress_required_validations = true (or config.anyway_config.suppress_required_validations = true)

• Use some custom env var to toggle this setting, e.g., ANYWAY_SUPPRESS_VALIDATIONS=true

• For Rails apps, set this parameter to true if the SECRET_KEY_BASE_DUMMY is defined (and ANYWAY_SUPPRESS_VALIDATIONS is not).

[OlegChuev]

@palkan I could start working on this feature if you don't mind