skip dependency step when cache exists

.ci/azure-pipelines.yml

@@ -40,9 +40,11 @@ jobs:
       inputs:
         key: 'yarn | yarn.lock'
         path: 'node_modules'
+        cacheHitVar: CACHE_RESTORED
 
     - script: 'yarn install --pure-lockfile'
       displayName: 'Install Dependencies'
+      condition: ne(variables.CACHE_RESTORED, 'true')
 
     - script: 'yarn build:development'
       displayName: 'Build Development'