fix(deps): update dependency vuepress to v2.0.0-beta.50-pre.1

Author: renovate[bot]

package.json

@@ -44,7 +44,7 @@
   "dependencies": {
     "@vuepress/client": "2.0.0-beta.61",
     "vue": "3.2.47",
-    "vuepress": "2.0.0-beta.61",
+    "vuepress": "2.0.0-beta.50-pre.1",
     "vuepress-theme-hope": "2.0.0-beta.190"
   },
   "devDependencies": {