Add dry-run option

action.yml

@@ -11,6 +11,10 @@ inputs:
   restore-keys:
     description: 'An ordered list of keys to use for restoring stale cache if no cache hit occurred for key. Note `cache-hit` returns false in this case.'
     required: false
+  dry-run:
+    description: 'Skip downloading cache. Only check if cache entry exists'
+    required: false
+    default: "false"
   upload-chunk-size:
     description: 'The chunk size used to split up large files during upload, in bytes'
     required: false