chore(release): 🔧 remove unused @release-it/bumper plugin

* Removed the `@release-it/bumper` plugin from `.release-it.json` and `package.json` as it is no longer needed.
* Updated the `package-lock.json` to reflect these changes.

Author: spirit-wiegmann

.release-it.json

@@ -27,12 +27,6 @@
     "after:release": "echo Successfully released ${name} v${version} to ${repo.repository}."
   },
   "plugins": {
-    "@release-it/bumper": {
-      "out": [
-        "package.json",
-        "proxy/package.json"
-      ]
-    },
     "@release-it/conventional-changelog": {
       "preset": "conventionalcommits",
       "infile": "CHANGELOG.md",