Fix keyword-as-hash handling for methods without keyword params

[pvcresin]

This PR fixes TypeProf’s handling of calls like foo(x: 1) when the callee does not declare keyword parameters.(scenario/known-issues/keywords.rb.)

def foo(a)
  a
end

foo(x: 1)

In those cases, keyword arguments are now treated as a trailing positional hash (Ruby-compatible), improving inference from untyped to record/hash types.

Details

• Track Prism::NoKeywordsParameterNode (**nil) as no_keywords in method AST metadata.
• Add ActualArguments#with_keywords_as_last_positional_hash to centralize argument normalization.
• Normalize keyword args in MethodDefBox#pass_arguments only when:
  • keyword args are present,
  • the method has no required/optional/rest keyword params,
  • and the method is not **nil.
• Promote the scenario from scenario/known-issues/keywords.rb to scenario/args/keyword-as-hash.rb.

[mame]

👏👏👏