Don't test on pypy, add more gc.collect()

Author: davidbrochart

.github/workflows/ci.yml

@@ -23,9 +23,6 @@ jobs:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
         python-version: ["3.11", "3.12", "3.13"]
-        include:
-          - os: ubuntu-latest
-            python-version: "pypy-3.11"
     steps:
       - name: Checkout
         uses: actions/checkout@v4

tests/test_kernelapp.py

@@ -1,3 +1,4 @@
+import gc
 import json
 import os
 import threading
@@ -30,6 +31,7 @@ def test_blackhole():
 
 
 def test_start_app():
+    gc.collect()
     app = IPKernelApp()
     app.kernel = MockKernel()