fix: use sha1 for hash instead of unsupported xxhash3-xxh64

packages/opencode/src/util/hash.ts

@@ -2,6 +2,6 @@ import { createHash } from "crypto"
 
 export namespace Hash {
   export function fast(input: string | Buffer): string {
-    return createHash("xxhash3-xxh64").update(input).digest("hex")
+    return createHash("sha1").update(input).digest("hex")
   }
 }