Fix dataset path construction in transfer_learning.ipynb tutorial

[athulya-anil]

This PR fixes the incorrect dataset path in the Cats vs Dogs transfer learning tutorial.
Previously the tutorial used:

PATH = os.path.join(os.path.dirname(path_to_zip), 'cats_and_dogs_filtered')

which caused a NotFoundError in Colab / TF 2.19.

This PR updates it to:

PATH = os.path.join(path_to_zip, 'cats_and_dogs_filtered')

Tested locally on Colab with TF 2.19 and it resolves the issue.

This PR fixes #101115 - tensorflow/tensorflow#101115

[github-actions]

Preview

Preview and run these notebook edits with Google Colab:

• site/en/tutorials/images/transfer_learning.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 fix-cats-dogs-path