Update dependency hexo to v7 [SECURITY]

Author: renovate[bot]

package.json

@@ -6,7 +6,7 @@
     "version": "3.8.0"
   },
   "dependencies": {
-    "hexo": "3.8.0",
+    "hexo": "7.2.0",
     "hexo-browsersync": "0.2.0",
     "hexo-deployer-git": "0.2.0",
     "hexo-generator-archive": "0.1.5",