Forbid const generics on abis

[xunilrj]

Description

This PR forbids "const generics" on abis. The reason is that to correctly support it, we will need to introduce changes to the ABI json.

This will be reserved to the future.

Checklist

• I have linked to any relevant issues.
• I have commented my code, particularly in hard-to-understand areas.
• I have updated the documentation where relevant (API docs, the reference, and the Sway book).
  • If my change requires substantial documentation changes, I have requested support from the DevRel team
• I have added tests that prove my fix is effective or that my feature works.
• I have added (or requested a maintainer to add) the necessary Breaking* or New Feature labels where relevant.
• I have done my best to ensure that my PR adheres to the Fuel Labs Code Review Standards.
• I have requested a review from the relevant team or maintainers.

---

Note

Disallows const generics in ABI method parameters/returns (including nested forms), adjusts type substitution to ignore const params, and adds failing tests to validate.

• ABI/type checking:
  • Add has_const_generics(..) to detect const generics in TypeInfo (including arrays/strings, nested structs/enums/tuples).
  • Enforce via TyAbiDecl::forbid_const_generics(..) emitting CompileError::ConstGenericNotSupportedHere for ABI interface fn params/returns and implementation items.
  • Invoke the check after constructing ty::TyAbiDecl in sway-core/src/semantic_analysis/ast_node/declaration/abi.rs.
• Type substitution:
  • In TypeSubstMap::from_superset_and_subset for Enum/Struct, use filter_map(|x| x.as_type_parameter()) so only type parameters participate in substitution (ignores const params).
• Tests:
  • Add should_fail/unsupported_const_generics with ABIs using const generics directly and via nested types; update snapshots and project files to expect errors.

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[codspeed-hq]

CodSpeed Performance Report

Merging #7483 will not alter performance

_{Comparing xunilrj/forbid-const-generics-on-abis (1bf3210) with master (886becb)}

Summary

✅ 25 untouched