docs: upgrade AudioSet URL shortener link to secure HTTPS

[ManvithPanyam]

Description

Upgrades an unencrypted HTTP hyperlink shortener link (http://g.co/audioset) to its secure HTTPS equivalent (https://g.co/audioset) within the audio transfer learning tutorial notebook.

Motivation and Context

Using cleartext HTTP links causes unnecessary network redirect latency and goes against modern security practices for standard documentation web nodes.

Types of Changes

• Documentation update (non-breaking change which fixes an issue)

[github-actions]

Preview

Preview and run these notebook edits with Google Colab:

• site/en/tutorials/audio/transfer_learning_audio.ipynb

Rendered notebook diffs available on ReviewNB.com.

Format and style

Use the TensorFlow docs notebook tools to format for consistent source diffs and lint for style:

$ python3 -m pip install -U --user git+https://github.com/tensorflow/docs

$ python3 -m tensorflow_docs.tools.nbfmt notebook.ipynb

$ python3 -m tensorflow_docs.tools.nblint --arg=repo:tensorflow/docs notebook.ipynb

If commits are added to the pull request, synchronize your local branch: git pull origin hunt-broken-links