fix: tag latest is never pulled despite Always pullPolicy

.gitlab-ci.yml

 variables:
   GITLAB_PASTEUR_PROJECT_ID: 6531
   PROJECT_NAME: nyxui
+  LARVATAGGER_IMAGE_TAG: 0.20.1-bigfat
 
 stages:
   - build
@@ -100,6 +101,7 @@ deploy to dev.pasteur.cloud:
     LT_LIMITS_CPU: "2"
     LT_LIMITS_MEMORY: "5Gi"
     LT_LIMITS_STORAGE: "2Gi"
+    LT_IMAGE_TAG: "$LARVATAGGER_IMAGE_TAG"
   environment:
     name: k8sdev-01/nyx-dev
     url: https://nyx.dev.pasteur.cloud
@@ -112,7 +114,7 @@ build larvatagger backend:
   extends: .build-with-buildah
   variables:
     IMAGE_NAME: "larvatagger"
-    IMAGE_TAG: "0.20.1-bigfat"
+    IMAGE_TAG: "$LARVATAGGER_IMAGE_TAG"
     BUILD_CONTEXT: "back"
     CONTAINERFILE: "back/Containerfile.larvatagger"
   rules: