Remove build rule for py2-futures am: f0f735cd81 am: b41ab41666 am: f68e4888a6 am: b8397c5d0c

Original change: https://android-review.googlesource.com/c/platform/external/python/futures/+/1903710

Change-Id: I0bc6e950abf47f46db95dcd76d15cfa5630369e0