fix(codegen): generate Array<Record<string, any>> for {:array, :map} return types

[barnabasJ]

Summary

• Actions returning {:array, :map} were incorrectly generating Record<string, any> instead of Array<Record<string, any>> in TypeScript
• Added :array_of_unconstrained_map variant to ActionIntrospection, following the existing pattern used for :array_of_typed_map, :array_of_typed_struct, etc.
• Updated all call sites in pipeline.ex, function_core.ex, and result_types.ex to handle the new variant

Test plan

• Added test for get_custom_data_list action returning {:array, :map}
• Added regression test verifying non-array Record<string, any> is unchanged
• Added integration test verifying array of maps is returned correctly at runtime
• All existing tests pass (1799 tests, 0 failures)
• TypeScript compilation checks pass (compileGenerated, shouldPass, shouldFail, testZod)
• mix format, mix credo --strict, mix compile --warnings-as-errors all pass

[Torkan]

Sorry for taking so long @barnabasJ! 🙈