doc: bump sphinx>=3.3.0
doc: bump sphinx>=3.3.0

The filters were updated to match the 3.3.0 generated text, so update
the sphinx requirement to exclude versions that use different text.

Signed-off-by: Peter Bigot <a4112a160b558d5427af084318038e19a95979ee@nordicsemi.no>

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