CODEOWNERS: Remove alwa-noric from bluetooth mesh

[alwa-nordic]

Removes alwa-nordic from the following paths: /tests/bluetooth/bsim_bt/bsim_test_mesh/ /tests/bluetooth/mesh_shell

This is done by adding new definitions for those paths, inheriting the owners of the previously matching rule, but without alwa-nordic.

Signed-off-by: Aleksander Wasaznik [email protected]