Update .dockerignore to match all sub-directories under src/rust named
'target', not just src/rust/target, to include target directories that
can arise from building crates individually.
.pids
.yarn
build-support/grapl-venv
-src/rust/target/**
+
+# match any directory named 'target', which can result from building creates
+# individually as one might do during local development.
+src/rust/**/target/**
+
test_artifacts/**
