meta: remove Companion's `prepublishOnly` (#5220)

.github/CONTRIBUTING.md

@@ -285,6 +285,12 @@ Now let’s create the version & tag:
 mkdir -p .git && npm version --workspaces-update=false --tag-version-prefix='@uppy/companion@' patch
 ```
 
+**Important:** Build Companion lib folder
+
+```bash
+yarn run build
+```
+
 Run a “dry-run” first:
 
 ```bash

packages/@uppy/companion/package.json

@@ -107,7 +107,6 @@
   "scripts": {
     "build": "tsc -p .",
     "deploy": "kubectl apply -f infra/kube/companion-kube.yml",
-    "prepublishOnly": "yarn run build",
     "start": "node ./lib/standalone/start-server.js",
     "test": "jest"
   },