fix: skip container image integration test on Windows CI

Windows CI runners use Windows containers and cannot pull Linux images.
This matches the pattern used by existing Lambda image build tests.

Author: singledigit

tests/integration/buildcmd/test_build_cmd_container_image.py

@@ -1,16 +1,20 @@
 """Integration test for ECS/AgentCore container image builds"""
 
-import os
 import shutil
 import tempfile
 from pathlib import Path
-from unittest import TestCase
+from unittest import TestCase, skipIf
 
 import yaml
 
 from samcli.commands.build.build_context import BuildContext
+from tests.testing_utils import CI_OVERRIDE, IS_WINDOWS, RUNNING_ON_CI
 
 
+@skipIf(
+    (IS_WINDOWS and RUNNING_ON_CI) and not CI_OVERRIDE,
+    "Skip container image build tests on Windows CI (no Linux Docker support)",
+)
 class TestContainerImageBuild(TestCase):
     """Test that samdev build correctly handles ECS and AgentCore container resources."""