chore: automatically clear any unwanted directories in test_programs (

#5081)

# Description

## Problem\*

Closes #5035

## Summary\*

Alternative to #5035 which just deletes any test programs which don't
have a Nargo.toml file.

## Additional Context



## Documentation\*

Check one:
- [x] No documentation needed.
- [ ] Documentation included in this PR.
- [ ] **[For Experimental Features]** Documentation to be submitted in a
separate PR.

# PR Checklist\*

- [x] I have tested the changes locally.
- [x] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.

test_programs/rebuild.sh

@@ -8,6 +8,14 @@ process_dir() {
     local current_dir=$2
     local dir_name=$(basename "$dir")
 
+    if [[ ! -f "$dir/Nargo.toml" ]]; then
+      # This directory isn't a proper test but just hold some stale build artifacts
+      # We then delete it and carry on.
+      rm -rf $dir
+      return 0
+    fi
+
+
     if [[ ! -d "$current_dir/acir_artifacts/$dir_name" ]]; then
       mkdir -p $current_dir/acir_artifacts/$dir_name
     fi