test: update V8 trace events test expectations

The event "V8.GCScavenger" is soon to be deprecated. Most of V8
trace events are either behind flags and disabled by default, or
are emitted infrequently. Instead of replacing "V8.GCScavenger"
with some other random event, this patch updates the tests to
check that there is some event in the category "v8" whose name
starts with "V8.".

PR-URL: #42120
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Mestery <mestery@protonmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

test/parallel/test-trace-events-all.js

@@ -27,7 +27,7 @@ proc.once('exit', common.mustCall(() => {
         return false;
       if (trace.cat !== 'v8')
         return false;
-      if (trace.name !== 'V8.GCScavenger')
+      if (!trace.name.startsWith('V8.'))
         return false;
       return true;
     }));

test/parallel/test-trace-events-v8.js

@@ -29,7 +29,7 @@ proc.once('exit', common.mustCall(() => {
         return false;
       if (trace.cat !== 'v8')
         return false;
-      if (trace.name !== 'V8.GCScavenger')
+      if (!trace.name.startsWith('V8.'))
         return false;
       return true;
     }));