test: prevent extraneous HOSTNAME substitution in test-runner-output

PR-URL: https://github.com/nodejs/node/pull/58076
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Marco Ippolito <marcoippolito54@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Pietro Marchini <pietro.marchini94@gmail.com>
Reviewed-By: Chemi Atlow <chemi@atlow.co.il>

test/parallel/test-runner-output.mjs

@@ -37,7 +37,7 @@ function replaceJunitDuration(str) {
   return str
     .replaceAll(/time="[0-9.]+"/g, 'time="*"')
     .replaceAll(/duration_ms [0-9.]+/g, 'duration_ms *')
-    .replaceAll(hostname(), 'HOSTNAME')
+    .replaceAll(`hostname="${hostname()}"`, 'hostname="HOSTNAME"')
     .replace(stackTraceBasePath, '$3');
 }