Remove `clone` shim logic for arrays

[RyanGlScott]

As of rust-lang/rust#86041, Clone impls for array types are now implemented in library code rather than using clone shims. As such, the TyKind::Array case in mir-json's clone shim logic is now unreachable, and we can remove it to simplify things:

mir-json/src/analyz/ty_json.rs

Line 392 in 3b2fafa

ty::TyKind::Array(t, _) => vec![t],