@uppy/companion: don't pin Yarn version in `package.json` (#3347)

Fixes: https://github.com/transloadit/uppy/issues/3356

bin/update-yarn.sh

@@ -28,8 +28,6 @@ echo "$PLUGINS" | xargs -n1 -t corepack yarn plugin remove
 
 cp package.json .yarn/cache/tmp.package.json
 sed "s#\"yarn\": \"$CURRENT_VERSION\"#\"yarn\": \"$LAST_VERSION\"#;s#\"yarn@$CURRENT_VERSION\"#\"yarn@$LAST_VERSION\"#" .yarn/cache/tmp.package.json > package.json
-cp packages/@uppy/companion/package.json .yarn/cache/tmp.package.json
-sed "s#\"yarn\": \"$CURRENT_VERSION\"#\"yarn\": \"$LAST_VERSION\"#;s#\"yarn@$CURRENT_VERSION\"#\"yarn@$LAST_VERSION\"#" .yarn/cache/tmp.package.json > packages/@uppy/companion/package.json
 rm .yarn/cache/tmp.package.json
 
 echo "$PLUGINS" | xargs -n1 -t corepack yarn plugin import

packages/@uppy/companion/package.json

@@ -112,9 +112,7 @@
     "test": "bash -c 'source env.test.sh && ../../../node_modules/jest/bin/jest.js'",
     "test:watch": "yarn test -- --watch"
   },
-  "packageManager": "yarn@3.1.0",
   "engines": {
-    "node": ">=10.20.1",
-    "yarn": "3.1.0"
+    "node": ">=10.20.1"
   }
 }