fix: pull op-rbuilder repo for tdx-quote-provider build

Author: 0x416e746f6e

l2/_unichain_builder/mkosi.build

@@ -33,7 +33,7 @@ build_rust_package \
 build_rust_package \
     "tdx-quote-provider" \
     "${TDX_QUOTE_PROVIDER_REF}" \
-    "https://github.com/flashbots/unichain-builder.git" \
+    "https://github.com/flashbots/op-rbuilder.git" \
     "" "" "-g"
 
 # build rproxy