fix CI

Author: Vipul-Cariappa

.github/workflows/CI.yml

@@ -513,7 +513,6 @@ jobs:
             nlohmann_json
             python=3.10
             bison=3.4
-            xeus=5.1.0
             xeus-zmq=3.0.0
 
       - uses: hendrikmuhs/ccache-action@main

ci/environment.yml

@@ -7,7 +7,7 @@ dependencies:
   - toml
   - pytest
   - jupyter
-  - xeus=1.0.1
+  - xeus=5.1.0
   - xtl
   - nlohmann_json
   - cppzmq