eni: Allow selecting subnet by Name tag
eni: Allow selecting subnet by Name tag

Currently the subnet-tag with key "Name" is not treated as a tag so
we can't select a subnet by specifying a Name tag.
This allows to select subnet by Name tag.

Fixes: #9428

Signed-off-by: Jaff Cheng <99154de6adbd9e51f9917403229e99ed58e4e4f8@gmail.com>

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