Fix missing `preact.h` import, enable lint for that

Fixes #2539

.eslintrc.json

@@ -15,6 +15,7 @@
     "jsx-quotes": ["error", "prefer-double"],
     "compat/compat": ["error"],
     "react/jsx-handler-names": ["warn"], // maybe we want to do this in the future?
+    "react/react-in-jsx-scope": ["error"],
 
     "jsdoc/check-alignment": ["warn"],
     "jsdoc/check-examples": ["warn"],

packages/@uppy/dashboard/src/index.js

@@ -1,3 +1,4 @@
+const { h } = require('preact')
 const { Plugin } = require('@uppy/core')
 const Translator = require('@uppy/utils/lib/Translator')
 const DashboardUI = require('./components/Dashboard')