Revert failing dependency updates (#242)

* Revert "Upgrade: Bump @vuepress/plugin-back-to-top"

This reverts commit 6df34ef39e.

* Revert "Upgrade: Bump @vuepress/plugin-search"

This reverts commit 3cfce26bce.

* Revert "Upgrade: Bump @vuepress/bundler-vite from 2.0.0-beta.25 to 2.0.0-beta.39"

This reverts commit e9cbb20e9b.

* Revert "Upgrade: Bump vuepress from 2.0.0-beta.25 to 2.0.0-beta.39"

This reverts commit 5b0baad589.

package.json

@@ -10,16 +10,16 @@
     "@types/jquery": "^3.5.6",
     "@types/mermaid": "^8.2.7",
     "@types/node": "^16.9.1",
-    "@vuepress/bundler-vite": "^2.0.0-beta.39",
-    "@vuepress/plugin-back-to-top": "^2.0.0-beta.38",
+    "@vuepress/bundler-vite": "^2.0.0-beta.25",
+    "@vuepress/plugin-back-to-top": "^2.0.0-beta.25",
     "@vuepress/plugin-debug": "^2.0.0-beta.25",
-    "@vuepress/plugin-search": "^2.0.0-beta.38",
+    "@vuepress/plugin-search": "^2.0.0-beta.25",
     "postcss-loader": "^6.1.1",
     "prettier": "^2.4.0",
     "sass": "^1.39.2",
     "sass-loader": "^12.1.0",
     "vue-property-decorator": "^9.1.2",
-    "vuepress": "^2.0.0-beta.39"
+    "vuepress": "^2.0.0-beta.25"
   },
   "scripts": {
     "docs:dev": "vuepress dev docs --clean-temp --clean-cache --host 127.0.0.1",