fix: thread_win on prefixed build

boring-sys/build/prefix.rs

@@ -73,6 +73,7 @@ pub fn prefix_symbols(config: &Config) {
         })
         .filter_map(|l| l.split_whitespace().nth(2).map(|s| s.to_string()))
         .filter(|l| !l.starts_with("_"))
+        .filter(|l| l != "p_thread_callback_boringssl") // `/ALTERNATENAME` didn't work for this so skip it
         .map(|l| format!("{l} {PREFIX}_{l}"))
         .collect();
     redefine_syms.sort();