Fix backend tests to resolve the error ensure "done()" is called

[yacchin1205]

The backend test of etherpad-lite was outputting the following error:

 1) export alignment to HTML
       when pad text is left aligned
         returns HTML with Subscript HTML tags:
     Error: Timeout of 120000ms exceeded. For async tests and hooks, ensure "done()" is called; if returning a Promise, ensure it resolves. (/home/runner/work/etherpad-lite/etherpad-lite/node_modules/ep_align/static/tests/backend/specs/exportHTML.ts)
      at listOnTimeout (node:internal/timers:573:17)
      at process.processTimers (node:internal/timers:514:7)

The test (when pad text is left aligned - returns HTML with Subscript HTML tags) defined done as an argument even though it does not call done, and removing it seemed to resolve this error.
(The other returns HTML with Subscript HTML tags tests also do not define done as an argument.)

[yacchin1205]

I have found that the backend tests of ep_align with ep_headings2 shows the following error, and will attempt to resolve.

  1) export alignment to HTML
       when pad text is heading
         returns HTML with Subscript HTML tags:
     Error: No left tag detected
      at Test.<anonymous> (/home/ubuntu/etherpad-lite/node_modules/.pnpm/ep_align@0.3.94/node_modules/ep_align/static/tests/backend/specs/exportHTML.ts:175:30)
      at Test.assert (/home/ubuntu/etherpad-lite/node_modules/.pnpm/supertest@7.0.0/node_modules/supertest/lib/test.js:172:8)
      at localAssert (/home/ubuntu/etherpad-lite/node_modules/.pnpm/supertest@7.0.0/node_modules/supertest/lib/test.js:120:14)
      at /home/ubuntu/etherpad-lite/node_modules/.pnpm/supertest@7.0.0/node_modules/supertest/lib/test.js:125:7
      at callback (/home/ubuntu/etherpad-lite/node_modules/.pnpm/superagent@9.0.2/node_modules/superagent/src/node/index.js:887:12)
      at <anonymous> (/home/ubuntu/etherpad-lite/node_modules/.pnpm/superagent@9.0.2/node_modules/superagent/src/node/index.js:1165:18)
      at IncomingMessage.<anonymous> (/home/ubuntu/etherpad-lite/node_modules/.pnpm/superagent@9.0.2/node_modules/superagent/src/node/parsers/json.js:19:7)
      at IncomingMessage.emit (node:events:530:35)
      at IncomingMessage.emit (node:domain:488:12)
      at endReadableNT (node:internal/streams/readable:1696:12)
      at process.processTicksAndRejections (node:internal/process/task_queues:82:21)

[yacchin1205]

Details of the No left tag detected error are as follows. I revised the expected pattern, as it looks functional.

Expected: <h1 style=\'text-align:left\'>Hello world</h1><br><br></body></html>
Actual: <h1 style=\'text-align:left\'>Hello world</h1><br><br></body></html>
(Actual has one more blank than Expected.)

[SamTV12345]

Thanks for the fix. Really appreciated. I took a look at the code forever and couldn't find the error