(nextjs) fixed cache path

.drone.yml

@@ -16,14 +16,10 @@ steps:
     settings:
       backend: "filesystem"
       restore: true
-      filesystem_cache_root: "/tmp"
       cache_key: '{{ .Repo.Name }}_{{ checksum "package.json" }}_{{ checksum "yarn.lock" }}_{{ arch }}_{{ os }}'
       archive_format: "gzip"
       mount:
         - '/app/node_modules'
-    volumes:
-      - name: cache
-        path: /tmp
   - name: build-master
     image: plugins/docker
     when:
@@ -74,3 +70,6 @@ steps:
         from_secret: global_docker_registry
       repo:
         from_secret: docker_repo
+volumes:
+  - name: cache
+    path: /tmp/drone-cache