contrib: add desktop notifications to checkpr
contrib: add desktop notifications to checkpr

Use notify-send in addition to audio bell to tell users when Jenkins has
finished testing the PR.

Signed-off-by: Quentin Monnet <d6b8e48afb2534b213e391cab43016505747a234@isovalent.com>

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