Use Node 14 on CI (#12512)

* Use Node 14 on CI

Node 14 is sufficiently stable now, use it on CI.

* also run build on node 14

Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: zeripath <art27@cantab.net>

.drone.yml

@@ -13,13 +13,13 @@ workspace:
 steps:
   - name: deps-frontend
     pull: always
-    image: node:12
+    image: node:14
     commands:
       - make node_modules
 
   - name: lint-frontend
     pull: always
-    image: node:12
+    image: node:14
     commands:
       - make lint-frontend
     depends_on: [deps-frontend]
@@ -36,7 +36,7 @@ steps:
 
   - name: checks-frontend
     pull: always
-    image: node:12
+    image: node:14
     commands:
       - make checks-frontend
     depends_on: [deps-frontend]
@@ -50,7 +50,7 @@ steps:
 
   - name: build-frontend
     pull: always
-    image: node:10 # this step is kept at the lowest version of node that we support
+    image: node:14
     commands:
       - make frontend
     depends_on: [lint-frontend]