Capture pythonx init output in tests

test/livebook/runtime/evaluator_test.exs

@@ -11,6 +11,8 @@ defmodule Livebook.Runtime.EvaluatorTest do
     # code evaluation. Testing pyproject.toml evaluation is tricky
     # because it requires a separate VM, so we only rely on the LV
     # integration tests.
+
+    ExUnit.CaptureIO.capture_io(fn ->
       Pythonx.uv_init("""
       [project]
       name = "project"
@@ -18,6 +20,9 @@ defmodule Livebook.Runtime.EvaluatorTest do
       requires-python = "==3.13.*"
       dependencies = []
       """)
+    end)
+
+    :ok
   end
 
   setup ctx do