Experimental UI Tests flag && improvements

[marinofelipe]

• Adds missing experimental flag for mapping the UI Test Targets to run
• Updates the test action with such a flag and changes inputs from snake case to kebab case

[Copilot]

Pull Request Overview

This PR adds experimental support for UI test targets in the SPM graph testing functionality. The main purpose is to allow the tool to optionally include UI test targets when determining which tests to run based on affected dependencies.

• Adds a new experimental flag experimentalUITestTargets to enable UI test target mapping
• Updates the GitHub Action to use kebab-case input parameters instead of snake_case
• Implements logic to read UI test dependencies from a JSON file and include them in test selection

Reviewed Changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 4 comments.

File	Description
Sources/SPMGraphTests/SPMGraphTests.swift	Adds experimental UI test targets support with JSON dependency mapping
Sources/SPMGraphExecutable/Subcommands/Tests.swift	Adds command-line flag for experimental UI test feature
.github/actions/tests/action.yml	Updates input parameter names to kebab-case and adds UI test flag

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[Copilot]

Debug print statements should be removed or replaced with proper logging that respects the verbose flag. These hardcoded print statements will always output regardless of the verbose setting.

Suggested change

	print(">>> file exists")
	if input.verbose {
	try system.echo(">>> file exists")
	}