Merge pull request 'ci: fix woodpecker definitions to comply with woodpecker 3' (#935) from woodpecker3 into main

Reviewed-on: Deuxfleurs/garage#935
Reviewed-by: maximilien <me@mricher.fr>

.woodpecker/publish.yaml

@@ -20,8 +20,9 @@ steps:
 
   - name: multiarch-docker
     image: nixpkgs/nix:nixos-22.05
-    secrets:
-      - docker_auth
+    environment:
+      DOCKER_AUTH:
+        from_secret: docker_auth
     commands:
       - mkdir -p /root/.docker
       - echo $DOCKER_AUTH > /root/.docker/config.json

.woodpecker/release.yaml

@@ -60,8 +60,8 @@ steps:
     environment:
       DOCKER_PLATFORM: "linux/${ARCH}"
       CONTAINER_NAME: "dxflrs/${ARCH}_garage"
-    secrets:
-      - docker_auth
+      DOCKER_AUTH:
+        from_secret: docker_auth
     commands:
       - mkdir -p /root/.docker
       - echo $DOCKER_AUTH > /root/.docker/config.json