Replace MinIO usage within Molecule scenarios with Garage

What does this MR do?

This merge request refactors the GET testing infrastructure to improve organization and consistency. The main changes include:

Infrastructure upgrades: The CI pipeline now uses larger compute resources (large instead of medium) and updates Docker to version 26 for better performance during testing.

Standardized naming: All test scenarios now use consistent naming patterns for clusters, networks, and configuration files, making the codebase easier to maintain and understand.

Simplified storage setup: The complex MinIO object storage system has been replaced with a simpler Garage storage solution, reducing configuration complexity while maintaining the same functionality.

Enhanced external services: Redis has been added as an external service alongside PostgreSQL, and both now use cleaner hostname references instead of hardcoded IP addresses.

Better error handling: New health check and debugging capabilities have been added to help diagnose issues when tests fail, including automatic collection of pod status and network information.

Consolidated configuration: Multiple separate configuration files have been merged into a single, unified template that works across all test scenarios, reducing duplication and maintenance overhead.

These changes make the testing environment more reliable, easier to debug, and simpler to maintain while preserving all existing functionality.

Related issues

Author's checklist

When ready for review, the Author applies the workflowready for review label and mention @gitlab-org/software-delivery/get-maintainers:

• Merge request:
  • Corresponding Issue raised and reviewed by the GET maintainers team.
  • Merge Request Title and Description are up-to-date, accurate, and descriptive
  • MR targeting the appropriate branch
  • MR has a green pipeline
  • MR has no new security alerts in the widget from the Secret Detection and IaC Scan (SAST) jobs.
• Code:
  • Check the area changed works as expected across all expected permutations.
  • Check that the changes work across upgrades.
  • Documentation created/updated in the same MR if applicable