chore: untrack environment-specific files and update .gitignore

[LouKanger]

Description

This PR updates the repository's .gitignore to include standard exclusions for Python development and IDE settings. It also untracks these files from the repository's history to ensure the codebase remains clean and environment-agnostic.

Why is this necessary?

• Security: Excluding .env prevents sensitive credentials and API keys from being accidentally committed. Not that they needed for this code to be functional, but it avoids leaking them from another project by accident.
• Performance: Excluding __pycache__ and bytecode files prevents unnecessary merge conflicts and repo bloat.
• Consistency: Virtual environments (venv/) and build artifacts (dist/, build/) are specific to a user's local machine and should not be shared across the team.
• Editor Independence: Moving .vscode/ out of version control allows contributors to use their preferred editor settings without affecting others.

Changes

• Updated .gitignore with sections for:
  • VS Code: .vscode/
  • Python: venv/, __pycache__, and bytecode.
  • Security: .env
  • Packaging: dist/, build/, and .egg-info/
• Removed these files/folders from the Git index (using git rm --cached) so they are no longer tracked.

Why this PR?

Embarking on my open-source-software contribution journey, and having worked with LLE simulations before, i figured this is an first toe-dip into the waters of OSS development and contributions 😄