Update bindep.txt for doc builds
specifies that doc dependencies need the doc tag in bindep, use it.
Leave test environment in for transition period until we use the new
scripts.
build-essential [platform:dpkg test]
gcc [platform:rpm test]
-gettext [!platform:suse]
-gettext-runtime [platform:suse]
-graphviz [test]
+# gettext and graphviz are needed by doc builds only. For transition,
+# have them in both doc and test.
+# TODO(jaegerandi): Remove test once infra scripts are updated.
+gettext [!platform:suse doc test]
+gettext-runtime [platform:suse doc test]
+graphviz [doc test]
libffi-dev [platform:dpkg]
libffi-devel [platform:redhat]
libffi48-devel [platform:suse]
