fix(cmdeploy): remove broken venv

Failed on system upgrade with
Fatal Python error: init_fs_encoding: failed to get the Python codec of the filesystem encoding

cmdeploy/src/cmdeploy/deployers.py

@@ -98,6 +98,15 @@ def _install_remote_venv_with_chatmaild(deployer) -> None:
         dest=remote_dist_file,
     )
 
+    # Remove venv if its Python is broken, e.g., after OS release upgrade
+    server.shell(
+        name="remove stale chatmaild venv if python is broken",
+        commands=[
+            f"{remote_venv_dir}/bin/python -c 'import sys' 2>/dev/null"
+            f" || rm -rf {remote_venv_dir}",
+        ],
+    )
+
     pip.virtualenv(
         name=f"chatmaild virtualenv {remote_venv_dir}",
         path=remote_venv_dir,