fix(cpp): remove map runtime test until wasi-sdk supports map types

wasm-component-ld bundled with wasi-sdk 30 doesn't support the map
type encoding (0x63) in the component model binary format. The C++
map codegen is still validated by the codegen test. The runtime test
can be re-added when wasi-sdk ships a compatible wasm-component-ld.

Author: yordis