Add missing version-script.ts file.

This was referenced from the prerelease job but didn't make it into the original PR.

Author: kentonv

.github/version-script.ts

@@ -0,0 +1,23 @@
+import * as fs from "node:fs";
+import { execSync } from "node:child_process";
+async function main() {
+  try {
+    console.log("Getting current git hash...");
+    const stdout = execSync("git rev-parse --short HEAD").toString();
+    console.log("Git hash:", stdout.trim());
+
+    const path = "./package.json";
+    const packageJson = JSON.parse(fs.readFileSync(path, "utf-8"));
+    packageJson.version = `0.0.0-${stdout.trim()}`;
+    fs.writeFileSync(path, `${JSON.stringify(packageJson, null, 2)}\n`);
+  } catch (error) {
+    console.error(error);
+    process.exit(1);
+  }
+}
+
+main().catch((err) => {
+  // Build failures should fail
+  console.error(err);
+  process.exit(1);
+});