Release tool should not include cilium-cli-exclusive labelled PRs in changelog for cilium/cilium

[joestringer]

During #270 preparation, the changelog PR cilium/cilium@04a3a35 included a reference to cilium/cilium#35021 which is labelled as cilium-cli-exclusive, meaning that it has no impact on the cilium release. Therefore it shouldn't be included in the changelog for new cilium/cilium releases.

[chancez]

Im using the release tool in another repo that's bundling a few different separate "releasable" entities that need their own change logs, so this is relevant to me too. My initial thought is to use an include or exclude filter on a label that determines which entity is being released, but I haven't thought of it too deeply. For example using --label-filter $THE_ENTITY_BEING_RELEASED could work.

[joestringer]

I like that idea. We could integrate that very easily into the github workflows we use in cilium/cilium for generating the changelog.