Let the instance service account list a team's deadman switches

GET /api/teams/{id}/deadman/switches used requireTeamMember, which 404s
for the instance-scoped service account because it belongs to no team.
terdut-operator lists switches by name on every reconcile, so TerdutTeams
never became ready. Instance service accounts now pass, as they already do
for the write endpoints.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

charts/terdut-server/Chart.yaml

@@ -15,5 +15,5 @@ type: application
 # appVersion and image.tag in values.yaml no longer agree, and that is not an oversight:
 # image.tag stays "latest", which is what a local install actually pulls. appVersion is
 # metadata and drives nothing.
-version: 0.47.1
-appVersion: "v0.47.1"
+version: 0.47.2
+appVersion: "v0.47.2"