ci: skip docker network creation on Windows in setup-dual-e2e.sh

Windows Docker Desktop does not expose the bridge network plugin via the
v1 plugin registry, so `docker network create --driver bridge` fails.
Kind manages its own Docker network automatically on Windows, making
the manual creation unnecessary. Guard the block with an OSTYPE check
(msys* = Git Bash on Windows).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: JeffreyDallas

test/e2e/dual-cluster/setup-dual-e2e.sh

@@ -49,8 +49,13 @@ for i in $(seq 1 "${SOLO_CLUSTER_DUALITY}"); do
   kind delete cluster -n "${SOLO_CLUSTER_NAME}-c${i}" || true
 done
 
-docker network rm -f kind || true
-docker network create kind --scope local --subnet 172.19.0.0/16 --driver bridge
+# On Windows (Docker Desktop), the bridge network plugin is not available via the v1
+# plugin registry. Kind manages its own Docker network automatically on Windows, so
+# manual network creation is not needed and will fail. Skip it on Windows (msys/Git Bash).
+if [[ "$OSTYPE" != msys* ]]; then
+  docker network rm -f kind || true
+  docker network create kind --scope local --subnet 172.19.0.0/16 --driver bridge
+fi
 docker info | grep -i cgroup || true
 
 # Setup Helm Repos