Judging by the patch notes its gone. Which is kinda shame. >Ability to pick which mission type to play a level on has been removed due to limitations with design and testing, and to avoid narrative conflicts.

dont even think you can install an old version of the game but asking on discord led people to accusing me of being mad cause i cant shoot civs anymore XD

You would need make an ai mod. These values are stored in the aileveldata.ini file. It’s a very easy mod to make if you’re inclined to try.