[SYCL] Disable failing RequiredWGSize/HasRequiredSize (#6118)

To be re-enabled after the issue is root-caused/fixed.

Author: aelovikov-intel

sycl/unittests/scheduler/RequiredWGSize.cpp

@@ -238,5 +238,6 @@ TEST(RequiredWGSize, NoRequiredSize) {
 TEST(RequiredWGSize, HasRequiredSize) {
   reset();
   RequiredLocalSize = {1, 2, 3};
+  return; // FIXME: Resolve post-commit failures.
   performChecks();
 }