batches: support multiple target branches
Created by: LawnGnome
Closes #25228 (closed). Needs to be merged right before https://github.com/sourcegraph/src-cli/pull/662.
My thanks to @eseliger for the excellent pathfinding work here a few months back.
This implements the new branches
field, along with the precedence rules defined in #25228 (closed). There's also a new template variable so that branches can be named dynamically, which is essentially required for this to work.
I've tested this with SSBC and (with sourcegraph/src-cli#662) src
, and everything appears normal.