Update devcontainer kubectl installation to use supported release downloads

[Copilot]

This pull request updates the .devcontainer/Dockerfile to enhance tool installation flexibility, improve reliability, and allow easier version management for several development tools. The changes include parameterizing more tool versions, updating installation methods for key tools to be more robust and secure, and fixing repository URLs.

Tool installation improvements:

• Parameterized the OS and architecture for tool downloads using TARGETOS and TARGETARCH build arguments, enabling multi-architecture builds.
• Added version arguments for KIND, SONAR_SCANNER, and PMD, making it easier to update these tools without modifying the script logic. [1] [2]

Tool installation method updates:

• Updated kubectl installation to fetch the latest stable version dynamically, verify checksums, and use the new architecture parameters for safer and more flexible installs.
• Changed kind installation to use the version and architecture parameters, improving consistency and reliability.
• Improved sonar-scanner and pmd installations to leverage the new version arguments and ensure clean, repeatable installs. [1] [2]

Repository and source updates:

• Updated Grafana’s GPG key and repository URLs to their latest endpoints, ensuring continued access to official packages.- [x] Inspect the devcontainer Dockerfile and current failing installation steps

• Install local test dependencies and capture a baseline for devcontainer-related checks
• Audit all external installation URLs referenced by the devcontainer Dockerfile
• Update outdated or broken installation URLs and related extraction logic in the Dockerfile
• Run targeted devcontainer tests plus focused Docker builds for the updated install paths