test: increase coverage for assert/calltracker

1. test calls fn parameter is number
Refs: https://coverage.nodejs.org/coverage-51b43675067fafaa/lib/internal/assert/calltracker.js.html#L30

2. test calls fn parameter is undefined
Refs: https://coverage.nodejs.org/coverage-51b43675067fafaa/lib/internal/assert/calltracker.js.html#L33

PR-URL: #36728
Reviewed-By: Rich Trott <rtrott@gmail.com>

test/parallel/test-assert-calltracker-calls.js

@@ -64,3 +64,17 @@ assert.throws(
   () => callsfunc(),
   { message: msg }
 );
+
+{
+  const tracker = new assert.CallTracker();
+  const callsNoop = tracker.calls(1);
+  callsNoop();
+  tracker.verify();
+}
+
+{
+  const tracker = new assert.CallTracker();
+  const callsNoop = tracker.calls(undefined, 1);
+  callsNoop();
+  tracker.verify();
+}