[NFC] Add Sergey to CODEOWNERS of USM test (#455)

Signed-off-by: Sergey Kanaev <[email protected]>
Co-authored-by: Alexey Bader <[email protected]>

Author: sergei

.github/CODEOWNERS

@@ -64,8 +64,8 @@ SYCL/SeparateCompile @AlexeySachkov  @Fznamznon
 # Specialization constant
 SYCL/SpecConstants @kbobrovs
 
-# Specialization constant
-SYCL/USM @jbrodman
+# Unified Shared Memory (USM)
+SYCL/USM @jbrodman @sergey-semenov
 
 # Stream
 SYCL/Basic/stream @againull