Improve testing support

[AmaranthineCodices]

This will allow us to test SDK-related features again in the aftermath of #5.

[Copilot]

Pull Request Overview

This PR improves the testing support for SDK-related features by adding Pixi workspace testing capabilities and restructuring the test configuration to support multiple test environments.

• Adds Pixi workspace testing infrastructure with fixture files and dedicated test cases
• Restructures test configuration to support both default and Pixi-specific test environments
• Updates CI workflow to include Pixi setup and workspace initialization

Reviewed Changes

Copilot reviewed 10 out of 12 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
package.json	Simplifies test script by removing build cleanup step
fixtures/pixi-workspace/*	Adds new Pixi workspace fixture with configuration, source file, and Git settings
extension/test/reporter.ts	Updates test reporter formatting for pending tests
extension/*.test.pixi.ts	Adds Pixi-specific test files for pyenv and LSP functionality
.vscode-test.mjs	Restructures test configuration to support multiple test environments
.github/workflows/test.yaml	Adds Pixi setup and workspace initialization to CI workflow

[Copilot]

[nitpick] The change adds a hardcoded dash prefix to the test title. Consider using a consistent formatting pattern or making this configurable to maintain consistency with other test output formatting.

Suggested change

	console.log(indent(Base.color('pending', `- ${test.title}`)));
	console.log(indent(Base.color('pending', formatTestTitle('pending', test.title))));

[Copilot]

The dependency version is hardcoded to a specific development build. Consider using a more stable version or documenting the reason for this specific dev version to avoid future maintenance issues.

Suggested change

	modular = "25.5.0.dev2025071605"
	modular = "25.5.0"

[Copilot]

The test hardcodes the expected version string. This creates a tight coupling between the test and the fixture configuration, making maintenance difficult when updating versions.

Suggested change

	assert.strictEqual(sdk.version, '25.5.0.dev2025071605');
	const expectedVersion = await extension.pyenvManager!.getExpectedSDKVersion();
	assert.strictEqual(sdk.version, expectedVersion);