build: 🔨 checks on generated data package from template (#106)

# Description

Runs the justfile checks from the built data package created from the
template.

This depends on #101 and doesn't work without.

Closes #56 

This PR needs a quick review.

## Checklist

- [ ] Ran `just run-all`

Author: lwjohnst86

justfile

@@ -47,7 +47,8 @@ test:
     --data author_email="first.last@example.com" \
     --data review_team="@first-last/developers" \
     --data github_board_number=22
-  # TODO: Other checks/tests?
+  # Run checks in the generated test data package
+  (cd $test_dir/$test_name && just check-python check-spelling)
 
 # Clean up any leftover and temporary build files
 cleanup: