Trim passenv (tox>=2.8)

Committed via https://github.com/asottile/all-repos

tox.ini

diff --git a/tox.ini b/tox.ini
index 590783a..dd80ff6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,7 +3,6 @@
 
 [testenv]
 deps = -rrequirements-dev.txt
-passenv = HOME HOMEPATH PROGRAMDATA
 setenv =
     GIT_AUTHOR_NAME = "test"
     GIT_COMMITTER_NAME = "test"