ci: fix container build for parameter-setup

Follow-up to #4930, in which we inadvertently broken container builds,
due to a workspace dependency being introduced. We don't build container
images on every PR push, so CI passed fine, only failing when trying to
build/deploy post-merge. Tacked on a small change to address.

Refs #4933.

.dockerignore

@@ -16,3 +16,5 @@
 !deployments/relayer/
 # summonerd tool, for orchestrating contributions
 !tools/summonerd/
+# parameter setup tool, for wrangling circuit configuration
+!tools/parameter-setup/