Link `rpcrt4` on Windows in C example

examples/c-dataflow/run.rs

@@ -95,6 +95,7 @@ async fn build_c_node(root: &Path, name: &str, out_name: &str) -> eyre::Result<(
         clang.arg("-luser32");
         clang.arg("-lwinspool");
         clang.arg("-lwinhttp");
+        clang.arg("-lrpcrt4");
 
         clang.arg("-Wl,-nodefaultlib:libcmt");
         clang.arg("-D_DLL");
@@ -165,6 +166,7 @@ async fn build_c_operator(root: &Path) -> eyre::Result<()> {
         link.arg("-luser32");
         link.arg("-lwinspool");
         link.arg("-lwinhttp");
+        link.arg("-lrpcrt4");
 
         link.arg("-Wl,-nodefaultlib:libcmt");
         link.arg("-D_DLL");