test/e2e: fix network prune flake

Creating networks in a different dir is not parallel safe when running
containers on them as the network configs may end up using the same
bridge names which then causes conflicts on the host.

Fixes #23876

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

test/e2e/common_test.go

@@ -1410,6 +1410,9 @@ func WaitForService(address url.URL) {
 // This needs to be called for all test they may remove networks from other tests,
 // so netwokr prune, system prune, or system reset.
 // see https://github.com/containers/podman/issues/17946
+// Note that when using this and running containers with custom networks you must use the
+// ginkgo Serial decorator to ensure no parallel test are running otherwise we get flakes,
+// https://github.com/containers/podman/issues/23876
 func useCustomNetworkDir(podmanTest *PodmanTestIntegration, tempdir string) {
 	// set custom network directory to prevent flakes since the dir is shared with all tests by default
 	podmanTest.NetworkConfigDir = tempdir

test/e2e/network_test.go

@@ -695,7 +695,7 @@ var _ = Describe("Podman network", func() {
 		Expect(listAgain.OutputToStringArray()).Should(ContainElement("podman"))
 	})
 
-	It("podman network prune", func() {
+	It("podman network prune", Serial, func() {
 		useCustomNetworkDir(podmanTest, tempdir)
 		// Create two networks
 		// Check they are there