fix: fix the fix, obv!

Author: dimaqq

juju/client/proxy/kubernetes/proxy.py

@@ -39,7 +39,7 @@ def __init__(
             raise ValueError(f"Invalid port number: {remote_port}")
 
         if ca_cert:
-            with tempfile.NamedTemporaryFile(delete=True) as f:
+            with tempfile.NamedTemporaryFile(delete=False) as f:
                 f.write(bytes(ca_cert, "utf-8"))
             self.temp_ca_file = config.ssl_ca_cert = f.name