build: bump cac from 6.5.5 to 6.5.6 (#2157)

Author: Sun Haoran

packages/vuepress/package.json

@@ -31,7 +31,7 @@
   "dependencies": {
     "@vuepress/core": "^1.3.0",
     "@vuepress/theme-default": "^1.3.0",
-    "cac": "^6.5.5",
+    "cac": "^6.5.6",
     "envinfo": "^7.2.0",
     "opencollective-postinstall": "^2.0.2",
     "update-notifier": "^4.0.0"

yarn.lock

@@ -3485,10 +3485,10 @@ bytes@3.1.0:
   resolved "https://registry.yarnpkg.com/bytes/-/bytes-3.1.0.tgz#f6cf7933a360e0588fa9fde85651cdc7f805d1f6"
   integrity sha512-zauLjrfCG+xvoyaqLoV8bLVXXNGC4JqlxFCutSDWA6fJrTo2ZuvLYTqZ7aHBLZSMOopbzwv8f+wZcVzfVTI2Dg==
 
-cac@^6.5.5:
-  version "6.5.5"
-  resolved "https://registry.yarnpkg.com/cac/-/cac-6.5.5.tgz#fb7720ecb95988d1425e5b4a2db41f6c5cd6e672"
-  integrity sha512-DF1HgrY2BkyrY1+g3Fwk/HFUcycI1PHpV3hCCxHM9qAPe+nrIOKFbzej2uiWdAjw4ry5eSYVWR4MLQYp2nV5YA==
+cac@^6.5.6:
+  version "6.5.6"
+  resolved "https://registry.yarnpkg.com/cac/-/cac-6.5.6.tgz#0120e39c9e56a7ab6418b078e6ad0595f2982375"
+  integrity sha512-8jsGLeBiYEVYTDExaj/rDPG4tyra4yjjacIL10TQ+MobPcg9/IST+dkKLu6sOzq0GcIC6fQqX1nkH9HoskQLAw==
 
 cacache@^11.3.3:
   version "11.3.3"