Fix Windows Python spawning

src/python-runtime.ts

@@ -17,6 +17,7 @@ function splitCommandSpec(spec: string): string[] {
 function canRun(command: string, args: string[]): boolean {
   const result = spawnSync(command, [...args, "--version"], {
     encoding: "utf8",
+    shell: process.platform === "win32",
   });
   return result.error == null && result.status === 0;
 }