fix: add _computation after VVMContract.deploy

ensure _computation is set properly after VVMContract.deploy is run

boa/contracts/vvm/vvm_contract.py

@@ -66,6 +66,7 @@ def deploy(self, *args, contract_name=None, env=None, **kwargs):
         if contract_name is not None:
             # override contract name
             ret.contract_name = contract_name
+        ret._computation = computation
 
         if computation.is_error:
             ret.handle_error(computation)