Update translation of RBS abstract methods to conditionally call super

[jesse-shopify]

When translating signatures into RBS on abstract methods, use the following pattern instead of a raise:

def abstract_method = defined?(super) ? super : raise(NotImplementedError, "Abstract method called")

This requires sorbet support:

• Allow RBS abstract methods to conditionally call super sorbet/sorbet#9846

Questions

• When sorbet support ships, is it best to bump the minimum sorbet version to match?

[Morriar]

As a follow up, it would be nice to provide the replacement through the translator options:

# does not rewrite abstract methods
SorbetSigsToRBSComments.new(
  translate_abstract_methods: nil
)

# old behavior, uses only raise
SorbetSigsToRBSComments.new(
  translate_abstract_methods: "raise NotImplementedError, \"Abstract method called\""
)

# new behavior, uses defined super
SorbetSigsToRBSComments.new(
  translate_abstract_methods: "defined?(super) ? super : raise(NotImplementedError, \"Abstract method called\")"
)