feat(pluginpresets): deletion protection for plugin preset

[gciezkowski-acc]

Description

I implemented validation in the webhook to prevent the deletion of plugin presets when the greenhouse.sap/prevent-deletion annotation is present.

What type of PR is this? (check all applicable)

• 🍕 Feature
• 🐛 Bug Fix
• 📝 Documentation Update
• 🎨 Style
• 🧑‍💻 Code Refactor
• 🔥 Performance Improvements
• ✅ Test
• 🤖 Build
• 🔁 CI
• 📦 Chore (Release)
• ⏩ Revert

Related Tickets & Documents

Added tests?

• 👍 yes
• 🙅 no, because they aren't needed
• 🙋 no, because I need help
• Separate ticket for tests # (issue/pr)

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

Added to documentation?

• 📜 README.md
• 🤝 Documentation pages updated
• 🙅 no documentation needed
• (if applicable) generated OpenAPI docs for CRD changes

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes

[IvoGoman]

Please remove the unrelated commits from the PR. There are missing requirements from #804 will they be provided on separate PRs?

[gciezkowski-acc]

Please remove the unrelated commits from the PR. There are missing requirements from #804 will they be provided on separate PRs?

Fixed

[gciezkowski-acc]

Please remove the unrelated commits from the PR. There are missing requirements from #804 will they be provided on separate PRs?

@IvoGoman
Webhook ensures greenhouse.sap/prevent-deletion during PluginPreset Create admission - Done
Webhook ensures deletion is blocked in case the annotation is set - Done
Documentation of PluginPreset contains a section on how to delete a PluginPreset - Done
Tests to verify the added behavior - Done
Remove unrelated commits - Done