revert(ci-sizer): 🔥 revert image pin — no versioned images in registry

GoReleaser config uses 'dockers_v2' (invalid key, should be 'dockers')
so versioned container images were never pushed. Only :latest exists.
Reverting to :latest until CI pipeline is fixed to publish version tags.

Refs: IPCEICIS-9326

otc/dev.t09.de/stacks/ci-sizer/sizer-receiver/deployment.yaml

@@ -20,7 +20,7 @@ spec:
         fsGroup: 65534
       containers:
         - name: receiver
-          image: edp.buildth.ing/devfw-cicd/ci-sizer-receiver:v0.8.1
+          image: edp.buildth.ing/devfw-cicd/ci-sizer-receiver:latest
           imagePullPolicy: Always
           args:
             - --db=/data/metrics.db