ci: remove zk-circuits from smart contract tests

zk-circuits requires a complex multi-step build process (powers of tau ceremony,
circuit compilation, zkey generation) that isn't suitable for simple CI.
Removed from test matrix to avoid parse errors and build failures.

.gitea/workflows/smart-contract-tests.yml

@@ -114,7 +114,7 @@ jobs:
           # Ensure standard directories exist
           mkdir -p /var/lib/aitbc/data /var/lib/aitbc/keystore /etc/aitbc /var/log/aitbc
 
-          for project in packages/solidity/aitbc-token apps/zk-circuits; do
+          for project in packages/solidity/aitbc-token; do
             if [[ -d "$project" ]] && [[ -f "$project/package.json" ]]; then
               echo "=== Linting $project ==="
               cd "$project"