Remove BUILD_BROKEN_USES_SOONG_PYTHON2_MODULES

It's been available for over a year, lets progress the python3 migration
by removing it.

Bug: 203436762
Test: Presubmits
Change-Id: I46a6477ec65e98b7e6df5cc1359f676dcbd0f08e
diff --git a/python/python.go b/python/python.go
index 8726f02..01ac86c 100644
--- a/python/python.go
+++ b/python/python.go
@@ -264,10 +264,9 @@
 			variants = append(variants, pyVersion3)
 		}
 		if proptools.BoolDefault(props.Version.Py2.Enabled, false) {
-			if !ctx.DeviceConfig().BuildBrokenUsesSoongPython2Modules() &&
-				ctx.ModuleName() != "py2-cmd" &&
+			if ctx.ModuleName() != "py2-cmd" &&
 				ctx.ModuleName() != "py2-stdlib" {
-				ctx.PropertyErrorf("version.py2.enabled", "Python 2 is no longer supported, please convert to python 3. This error can be temporarily overridden by setting BUILD_BROKEN_USES_SOONG_PYTHON2_MODULES := true in the product configuration")
+				ctx.PropertyErrorf("version.py2.enabled", "Python 2 is no longer supported, please convert to python 3.")
 			}
 			variants = append(variants, pyVersion2)
 		}