[py] Update test_remote_webdriver.py to use file_names

[rdinoff]

files does not get returned in a consistent order from get_downloadable_files() which is why the sort is needed in the assert. Use file_names instead

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Motivation and Context

Types of changes

• Change to the site (I have double-checked the Netlify deployment, and my changes look good)
• Code example added (and I also added the example to all translated languages)
• Improved translation
• Added new translation (and I also added a notice to each document missing translation)

Checklist

• I have read the contributing document.
• I have used hugo to render the site/docs locally and I am sure it works.

[rdinoff]

SeleniumHQ#1568