Upgrade parsec_web to Hosted Package and Clean Up Local References

[rodiguif]

Description ✍️

This PR includes the following updates and clean-up tasks:

• Migrated parsec_web from a local path dependency to a hosted package on pub.dev (version ^0.1.2)
• Removed outdated .pubignore and pubspec.lock files from parsec_web as it's now a library package
• Updated web dependency to ^1.1.0 and removed deprecated js dependency
• Bumped version numbers in pubspec.yaml and CHANGELOG.md for both parsec and parsec_web
• Removed redundant .dart_tool/, .packages, and build/ from .gitignore and ensured Flutter-specific ignores are placed where needed

Overview 🔍

Overview of the feature if possible (screenshot, gif, etc)

Test Guidance

Explain how to test the changes of this Pull Request

[rodiguif]

@Victorcorcos Maybe the web package update is no longer compatible with older Flutter versions. Later, we need to improve those GitHub Actions workflows — it's enough to run the tests on a single version.