CI: k8sDatapathConfiguration tests cleanup when finished
CI: k8sDatapathConfiguration tests cleanup when finished

These tests each install a new cilium configuration, but never restored
what was previously in-place. This could result in cascading or
test-order-dependent CI failures. When finishing the default cilium
config for this test run is installed.

Signed-off-by: Ray Bejjani <7f525154e857f3d57a641a83dddc584f42addc6a@isovalent.com>

tklauser/cilium,michi-covalent/cilium,cilium/cilium,tklauser/cilium,tgraf/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,cilium-team/cilium,michi-covalent/cilium,michi-covalent/cilium,tklauser/cilium,tgraf/cilium,tgraf/cilium,tgraf/cilium,cilium/cilium,cilium-team/cilium,cilium/cilium,tklauser/cilium,tklauser/cilium,tgraf/cilium,michi-covalent/cilium,tgraf/cilium