Disable cilium e2e on Github Actions (#566)

Test is known to be flaky on the runners.

tests/integration/tests/test_cilium_e2e.py

@@ -2,6 +2,7 @@
 # Copyright 2024 Canonical, Ltd.
 #
 import logging
+import os
 import platform
 from typing import List
 
@@ -19,6 +20,10 @@
 @pytest.mark.skipif(
     ARCH not in CILIUM_CLI_ARCH_MAP, reason=f"Platform {ARCH} not supported"
 )
+@pytest.mark.skipif(
+    os.getenv("TEST_CILIUM_E2E") == "true",
+    reason="Test is known to be flaky on GitHub Actions",
+)
 def test_cilium_e2e(instances: List[harness.Instance]):
     instance = instances[0]
     instance.exec(["bash", "-c", "mkdir -p ~/.kube"])