maintainers: Add Al Semjonovs as collaborator for testing/emul
maintainers: Add Al Semjonovs as collaborator for testing/emul

Al is part of the core team working on testing & emulation at Google.
He should be added to reviews for changes pertaining to these.

Signed-off-by: Yuval Peress <50dc11c009bd4d7e9d9d15a383c1743ce5ee82ef@google.com>

galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr