chromeos-base/protofiles: add missing dependency

Add build dependency on dev-python/six. Normally this package
is available as a part of the SDK but in edge cases like python
version upgrade in the SDK it should be spelled out explicitly.

BUG=b/257113269
TEST=presubmit
RELEASE_NOTE=None

Change-Id: I6b5a033d0627f29491ea45a84caad4d2001b0c4f
Reviewed-on: https://cos-review.googlesource.com/c/third_party/overlays/chromiumos-overlay/+/42400
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
diff --git a/chromeos-base/protofiles/protofiles-0.0.68.ebuild b/chromeos-base/protofiles/protofiles-0.0.68.ebuild
index 2d5947b..5e2e771 100644
--- a/chromeos-base/protofiles/protofiles-0.0.68.ebuild
+++ b/chromeos-base/protofiles/protofiles-0.0.68.ebuild
@@ -74,7 +74,7 @@
 
 PYTHON_COMPAT=( python{3_6,3_7,3_8} )
 
-inherit cros-constants cros-workon eutils python-any-r1
+inherit cros-constants cros-workon eutils distutils-r1
 
 DESCRIPTION="Protobuf installer for the device policy proto definitions."
 HOMEPAGE="https://chromium.googlesource.com/chromium/src/components/policy"
@@ -100,6 +100,7 @@
 	"secure_connect.proto"
 )
 
+BDEPEND="dev-python/six[${PYTHON_USEDEP}]"
 RDEPEND="!<chromeos-base/chromeos-chrome-82.0.4056.0_rc-r1"
 
 src_compile() {