chore(artifactapi): deploy v3.7.3

Bumps the API and UI images from v3.6.5 to v3.7.3 so the au-syd1 cluster
picks up the recent fixes: local-repo files now appear in the cached-objects
UI, evicting a local RPM prunes its repodata metadata, and the bare domain
redirects to the web UI.

- api-deployment: artifactapi v3.6.5 -> v3.7.3
- ui-deployment: artifactapi-ui v3.6.5 -> v3.7.3

apps/base/artifactapi/ui-deployment.yaml

@@ -22,7 +22,7 @@ spec:
       automountServiceAccountToken: true
       containers:
         - name: ui
-          image: git.unkin.net/unkin/artifactapi-ui:v3.6.5
+          image: git.unkin.net/unkin/artifactapi-ui:v3.7.3
           imagePullPolicy: IfNotPresent
           ports:
             - containerPort: 80