[ie/zetland] Add ZetlandDKArticle Extractor

[HobbyistDev]

IMPORTANT: PRs without the template will be CLOSED

Description of your pull request and other information

This PR add site support for zetland.dk. This PR only test the OP url in #9024 as the other url require subscription. This PR only assume the article only contain 1 audio link with no other type of media

Fixes #9024

Template

Before submitting a pull request make sure you have:

• At least skimmed through contributing guidelines including yt-dlp coding conventions
• Searched the bugtracker for similar pull requests
• Checked the code with flake8 and ran relevant tests

In order to be accepted and merged into yt-dlp each piece of code must be in public domain or released under Unlicense. Check all of the following options that apply:

• I am the original author of this code and I am willing to release it under Unlicense
• I am not the original author of this code but it is in public domain or released under Unlicense (provide reliable evidence)

What is the purpose of your pull request?

• Fix or improvement to an extractor (Make sure to add/update tests)
• New extractor (Piracy websites will not be accepted)
• Core bug fix/improvement
• New feature (It is strongly recommended to open an issue first)

[bashonly]

please double check the test since the branching and description fixes may yield different results

[HobbyistDev]

The test looks fine to me:

> python devscripts/run_tests.py ZetlandDKArticleIE
Running ['pytest', '-Werror', '--tb=short', 'test/test_download.py::TestDownload::test_ZetlandDKArticle']
Running ['C:\\Users\\HobbyistDev\\Documents\\Program\\python_proj\\Scripts\\python.exe', '-Werror', '-m', 'unittest', 'test.test_download.TestDownload.test_ZetlandDKArticle']
[debug] Loaded 1825 extractors 
[ZetlandDKArticle] Extracting URL: https://www.zetland.dk/historie/sO9aq2MY-a81VP3BY-66e69?utm_source=instagram&utm_medium=linkibio&utm_campaign=artikel
[ZetlandDKArticle] sO9aq2MY-a81VP3BY-66e69: Downloading webpage
[debug] Formats sorted by: hasvid, ie_pref, lang, quality, res, fps, hdr:12(7), vcodec:vp9.2(10), channels, acodec, size, br, asr, proto, vext, aext, hasaud, source, id
[info] sO9aq2MY-a81VP3BY-66e69: Downloading 1 format(s): 2
[info] Writing video metadata as JSON to: test_ZetlandDKArticle_sO9aq2MY-a81VP3BY-66e69.info.json 
[debug] Invoking http downloader on "https://storage.googleapis.com/zetland-upload-production/07134420-b45f-11ee-b3a9-03589fc21889%2FJoannahusetafsnit1NYNYFINAL.mp3"
[debug] File locking is not supported. Proceeding without locking[download] Destination: test_ZetlandDKArticle_sO9aq2MY-a81VP3BY-66e69.mp3 
[download] 100% of   10.00KiB in 00:00:02 at 4.65KiB/s 
.
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Ran 1 test in 4.214s

OK