Update ghcr.io/nginxinc/kic-test-grpc-server Docker tag to v0.2.3 (nginx#2670)

| datasource | package                               | from  | to    |
| ---------- | ------------------------------------- | ----- | ----- |
| docker     | ghcr.io/nginxinc/kic-test-grpc-server | 0.2.2 | 0.2.3 |

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: miledxz

tests/suite/manifests/snippets-filter/grpc-backend.yaml

@@ -28,7 +28,7 @@ spec:
     spec:
       containers:
       - name: grpc-backend
-        image: ghcr.io/nginxinc/kic-test-grpc-server:0.2.2
+        image: ghcr.io/nginxinc/kic-test-grpc-server:0.2.3
         env:
         - name: POD_NAME
           valueFrom: