[chore] use clis instead of libs

[ChristofferNissen]

Change from using native go libraries to CLIs managed outside Helmper to reduce dependencies.

Add scanning to build pipeline

[Copilot]

Pull Request Overview

This PR transitions the project from using native Go libraries for scanning and patching to relying on external CLIs, thereby reducing dependencies and streamlining the build process. Key changes include:

• Replacing internal Trivy library usage in pkg/trivy/main.go with CLI invocation via os/exec.
• Removing pkg/copa/patch.go and refactoring patch functionality in pkg/copa/main.go to utilize external commands.
• Updating workflow steps to install and execute Trivy, and making minor improvements in condition checks and comment clarity.

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
pkg/trivy/main.go	Refactored scan function to use Trivy CLI and removed unused library imports.
pkg/flow/spsOption.go	Improved condition check for image count.
pkg/copa/util.go	Added SupportedOS helper with clear logic.
pkg/copa/patch.go	Removed outdated patch implementation.
pkg/copa/main.go	Updated patch execution to call external CLI and adjusted error messages.
internal/program.go	Reordered variable initialization for clarity.
internal/bootstrap/viper.go	Corrected a spelling mistake in a comment.
internal/bootstrap/helm.go	Minor import reorder.
.github/workflows/build.yml	Added steps to install Trivy and run file system scan.

Comments suppressed due to low confidence (2)

pkg/trivy/main.go:43

• [nitpick] Consider appending the command output (e.g. string(output)) to the error log to aid in diagnosing failures during Trivy CLI execution.

slog.Error("Trivy CLI execution failed", slog.Any("error", err))

pkg/copa/main.go:101

• [nitpick] For consistency, consider using the same image identifier (such as 'ref') in error messages instead of mixing identifiers (i.Tag) which might confuse troubleshooting.

return fmt.Errorf("error saving image %s to tar :: %w :: %s", i.Tag, err, string(output))