[MINOR] Include data files rather than downloading them

[Mark2000]

Description

Simplemaps wasn't liking us using the requests package to download the data, and I couldn't find a way to automate it. Packaging it with our software is okay according to their license since we have attribution.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How should this pull request be reviewed?

• By commit
• All changes at once

Checklist

• I have performed a self-review of my code
• I have commented my code in hard-to-understand areas
• I have made corresponding changes to the documentation and release notes
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works

[Copilot]

Pull Request Overview

This PR eliminates the need for a post-installation script by including world cities data files directly in the package rather than downloading them at install time. This addresses issues with Simplemaps not allowing automated downloads via the requests package.

• Removes the finish_install script and its downloading functionality
• Includes simplemaps world cities data files directly in the package with proper licensing
• Updates documentation to remove references to the post-installation step

Reviewed Changes

Copilot reviewed 7 out of 10 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/bsk_rl/finish_install.py	Simplified to only print a deprecation message instead of downloading data
src/bsk_rl/scene/targets.py	Updated docstring to remove reference to finish_install
src/bsk_rl/_dat/simplemaps_worldcities/license.txt	Added license file for included world cities data
pyproject.toml	Removed finish_install script entry point
docs/source/install.rst	Updated installation instructions to remove finish_install step
docs/source/index.rst	Updated quick start instructions to remove finish_install step
.github/actions/install-bsk-rl/action.yml	Updated CI installation to remove finish_install step

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.
You can also share your feedback on Copilot code review for a chance to win a $100 gift card. Take the survey.}

[LorenzzoQM]

I got scared for a second with the 40,000 new lines.

[Mark2000]

Haha yeah, couldn't think of a better way to do that and it shouldn't slow down cloning by too much.