chore: checkpoint before Python removal

vendor/wasip2/examples/hello-world.rs

@@ -0,0 +1,7 @@
+use std::io::Write as _;
+
+fn main() {
+    let mut stdout = wasip2::cli::stdout::get_stdout();
+    stdout.write_all(b"Hello, world!\n").unwrap();
+    stdout.flush().unwrap();
+}