test: stabilize exec resolver timeout fixture

src/secrets/resolve.test.ts

@@ -195,14 +195,14 @@ describe("secret ref resolver", () => {
 
   itPosix("uses timeoutMs as the default no-output timeout for exec providers", async () => {
     const root = await createCaseDir("exec-delay");
-    const scriptPath = path.join(root, "resolver-delay.mjs");
+    const scriptPath = path.join(root, "resolver-delay.sh");
+    // Keep the fixture cheap to start so this stays deterministic under a busy test run.
     await writeSecureFile(
       scriptPath,
       [
-        "#!/usr/bin/env node",
-        "setTimeout(() => {",
-        "  process.stdout.write(JSON.stringify({ protocolVersion: 1, values: { delayed: 'ok' } }));",
-        "}, 30);",
+        "#!/bin/sh",
+        "sleep 0.03",
+        'printf \'{"protocolVersion":1,"values":{"delayed":"ok"}}\'',
       ].join("\n"),
       0o700,
     );