Channing Tatum and Zoë Kravitz might not be together anymore, but they're still gonna be in a gang together, we're told ... 'cause neither of them are dropping out of the new flick "Alpha Gang."

Here's the deal ... yesterday, Deadline announced the cast for the new movie produced by and starring Cate Blanchett. Cast members include Dave Bautista, Steven Yeun, Léa Seydoux, Riley Keough -- and Tatum and Kravitz.

Despite the potential awkwardness of sharing the screen with an ex, production sources tell TMZ Channing and Zoë will absolutely be continuing their roles in "Alpha Gang," in spite of the split.

Sigh of relief for the producers of the flick ... 'cause the couple's breakup could've seriously messed with the project if the 2 weren't consummate professionals.

As we reported, Channing and Zoë will not be walking down the aisle after all ... with the pair splitting after more than 3 years together.

The pair got engaged last year, but Kravitz had recently been spotted without the rock on that finger. It's unclear when or why they split.

Both Channing and Zoë were going through divorces when they first got together ... though they've both since finalized settlements in their respective splits.