Update CODEOWNERS (#4465)

Replace @nik-suri with @mdulin2 as a CODEOWNER for `cosmwasm`

Author: nik-suri

.github/CODEOWNERS

@@ -7,7 +7,7 @@
 /algorand/ @evan-gray @kcsongor
 /aptos/ @kcsongor
 /bitcoin/ @evan-gray
-/cosmwasm/ @nik-suri @kcsongor
+/cosmwasm/ @mdulin2 @kcsongor
 /ethereum/ @gator-boi @kcsongor
 /ethereum/env/ @gator-boi @kcsongor @evan-gray
 /relayer/ethereum @nonergodic @gator-boi