Tweak cache volume definition

.drone.yml

@@ -8,7 +8,8 @@ steps:
     mount:
       - /usr/local/lib/R/site-library
     volumes:
-      - /tmp/cache:/cache
+      - name: cache
+        path: /cache
   - name: build quarto site
     image: cynkra/quarto-r:1.4.169-4.3.1
     commands:
@@ -48,4 +49,11 @@ steps:
     mount:
       - /usr/local/lib/R/site-library
     volumes:
-      - /tmp/cache:/cache
+      - name: cache
+        path: /cache
+
+
+volumes:
+- name: cache
+  host:
+    path: /tmp/drone/cache