Fix warning in resourceHandling test unit

[laurent22]

This test prints a warning that should be either prevented or disabled:

 PASS  gui/NoteEditor/utils/resourceHandling.test.js (7.314 s)
  ● Console

    console.warn
      10:43:11: resourceHandling: Error creating a resource for data:image/svg+xml;base64,==. Error: Not implemented
          at Object.fetchBlob (/joplin/packages/lib/shim.ts:250:9)
          at fetchBlob (/joplin/packages/app-desktop/gui/NoteEditor/utils/resourceHandling.ts:165:17)
          at Generator.next (<anonymous>)
          at /joplin/packages/app-desktop/gui/NoteEditor/utils/resourceHandling.js:27:67
          at new Promise (<anonymous>)
          at Object.<anonymous>.__awaiter (/joplin/packages/app-desktop/gui/NoteEditor/utils/resourceHandling.js:9:10)
          at processPastedHtml (/joplin/packages/app-desktop/gui/NoteEditor/utils/resourceHandling.js:162:10)
          at /joplin/packages/app-desktop/gui/NoteEditor/utils/resourceHandling.test.ts:17:34
          at Generator.next (<anonymous>)
          at fulfilled (/joplin/packages/app-desktop/gui/NoteEditor/utils/resourceHandling.test.js:12:24)
          at processTicksAndRejections (node:internal/process/task_queues:95:5)

      245 |                             }
      246 |
    > 247 |                             consoleObj[fn](...items);
          |                                           ^
      248 |                     } else if (target.type === 'file') {
      249 |                             const timestamp = moment().format('YYYY-MM-DD HH:mm:ss');
      250 |                             const line = [timestamp];

      at Logger.log (../utils/Logger.ts:247:19)
      at Object.log [as warn] (../utils/Logger.ts:120:50)
      at warn (gui/NoteEditor/utils/resourceHandling.ts:171:12)
      at gui/NoteEditor/utils/resourceHandling.js:27:67
      at Object.<anonymous>.__awaiter (gui/NoteEditor/utils/resourceHandling.js:9:10)
      at processPastedHtml (gui/NoteEditor/utils/resourceHandling.js:162:10)
      at gui/NoteEditor/utils/resourceHandling.test.ts:17:34
      at fulfilled (gui/NoteEditor/utils/resourceHandling.test.js:12:24)