Bump vue-property-decorator from 8.3.0 to 8.4.0

Bumps [vue-property-decorator](https://github.com/kaorun343/vue-property-decorator) from 8.3.0 to 8.4.0.
- [Release notes](https://github.com/kaorun343/vue-property-decorator/releases)
- [Commits](https://github.com/kaorun343/vue-property-decorator/commits)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -35,7 +35,7 @@
     "typescript": "^3.7.5",
     "vue-async-computed": "^3.8.2",
     "vue-class-component": "^7.2.2",
-    "vue-property-decorator": "^8.3.0"
+    "vue-property-decorator": "^8.4.0"
   },
   "devDependencies": {
     "@nuxt/typescript-build": "^0.5.6",