Fix compilation for wasm target

crates/solidity/Cargo.toml

@@ -49,9 +49,10 @@ libc = { workspace = true }
 inkwell = { workspace = true, features = ["target-riscv", "llvm18-0-no-llvm-linking"]}
 
 [features]
-default = ["parallel"]
+default = []
 parallel = ["rayon"]
 
 #TODO: Use pthreads -C target-feature=+atomics,+bulk-memory -Clink-arg=-pthread in compilation and enable `parallel` feature
-[target.'cfg(target_os = "emscripten")'.features]
-default = []
+# Enable parallel_native by default only for non-emscripten targets
+[target.'cfg(not(target_os = "emscripten"))'.features]
+default = ["parallel_native"]