Adapt Script Console for experimental Manage Jenkins UI (#2592)

Co-authored-by: Tim Jacomb <21194782+timja@users.noreply.github.com>

Author: janfaracik

src/main/java/org/jenkinsci/test/acceptance/po/Node.java

@@ -82,7 +82,7 @@ public String runScript(String script, int timeoutSeconds, Object... args) {
         visit("script");
         CodeMirror cm = new CodeMirror(this, "/script");
         cm.set(String.format(script, args));
-        clickButton("Run");
+        find(by.css("button[value='Run']")).click();
 
         waitFor(by.xpath("//h2[contains(text(), 'Result')]"), timeoutSeconds);