Add erocast extractor.

[madewokherd]

IMPORTANT: PRs without the template will be CLOSED

Description of your pull request and other information

Adds an extractor for erocast.me.

Fixes #4001

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)

Copilot Summary

🤖 Generated by Copilot at b13703f

Summary

📦🚚🎨

Add support for erocast.com videos by importing a new extractor class ErocastIE from erocast.py.

Walkthrough

[madewokherd]

Thanks, updated.

[bashonly]

LGTM. In the future, please avoid force pushing; it makes reviewing more difficult for us, and all commits will be squashed before merge anyways

[madewokherd]

Ah sorry, will keep that in mind for next time. Thanks for the review.

[Grub4K]

Additionally some of the whitespace should be condensed