feat: Implement Automated Publishing via Tag & Disable Dependabot

[vicajilau]

Description

This Pull Request introduces two key changes to our repository:

1. Automated Package Publishing: We are implementing automated publishing for our main Dart package. Following the official Dart recommendations (https://dart.dev/tools/pub/automated-publishing), pushing a new Git tag (e.g., v1.0.0, v1.0.1+hotfix.1) will now automatically trigger the publication of the package to pub.dev. This streamlines our release process and ensures consistent publishing.

   To achieve this, a new GitHub Actions workflow has been added (.github/workflows/publish.yml). This workflow listens for push events on tags and executes the dart pub publish --force command after a successful build and test run.

2. Dependabot Disablement: Dependabot has been disabled for the main Dart package. While Dependabot is valuable for certain projects, for our primary package, we prefer to manage dependencies manually and with more control. This decision aims to reduce noise from automated PRs and allows us to address dependency updates strategically during our development cycles.

   This has been configured in the .github/dependabot.yml file by setting open-pull-requests-limit: 0 for the Dart ecosystem, or by removing the Dart configuration entirely.

Changes Proposed:

• Added .github/workflows/publish.yml for automated package publishing.
• Modified .github/dependabot.yml to disable Dependabot for Dart dependencies.