Create artifacts directory

This directory should by used in case of test dependency to store tests
artifacts.

ref: t/org/software-supply-chain/production-pipeline/issues#131

eng/devenv/issues#9

Author: elsaferrara

src/e3/anod/buildspace.py

@@ -15,6 +15,7 @@ class BuildSpace:
     """Build space located inside a sandbox."""
 
     DIRS = (
+        "artifacts",
         "binary",
         "build",
         "install",