[CI] Remove unnecessary GitHub workflows

[winkletinkle]

Current Behavior

This repo doesn't need to perform any linting, building, or testing.

Desired Behavior

Most, but not all of the .github/workflows can be deleted.

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Contributor Guides and Handbook

• 🛠 Meshery Build & Release Strategy
• 📚 Instructions for contributing to documentation
• Meshery documentation site and source
• 🎨 Wireframes and designs for Meshery UI in Figma
• 🙋🏾🙋🏼 Questions: Discussion Forum and Community Slack
• 🧪 Meshery Test Plan Spreadsheet

[welcome]

Thanks for opening this issue. A contributor will be by to give feedback soon. In the meantime, please review the Contributors' Welcome Guide, engage in the discussion forum, and be sure to join the community Slack.