@uppy/utils: simplify `canvasToBlob` (#3080)

The built-in `HTMLCanvasElement#toBlob` is supported everywhere.

packages/@uppy/utils/src/canvasToBlob.js

@@ -1,5 +1,3 @@
-const dataURItoBlob = require('./dataURItoBlob')
-
 /**
  * Save a <canvas> element's content to a Blob object.
  *
@@ -7,12 +5,7 @@ const dataURItoBlob = require('./dataURItoBlob')
  * @returns {Promise}
  */
 module.exports = function canvasToBlob (canvas, type, quality) {
-  if (canvas.toBlob) {
-    return new Promise((resolve) => {
-      canvas.toBlob(resolve, type, quality)
-    })
-  }
-  return Promise.resolve().then(() => {
-    return dataURItoBlob(canvas.toDataURL(type, quality), {})
+  return new Promise((resolve) => {
+    canvas.toBlob(resolve, type, quality)
   })
 }