Check for unused baselines in CI, remove unused baselines

[jakebailey]

No description provided.

[Copilot]

Pull Request Overview

This PR aims to clean up the repository by removing unused baseline reference files and adding a new CI job to manage baselines automatically.

• Removed obsolete baseline files from submodule directories.
• Added a dedicated CI job in ci.yml to remove, accept, and check baselines, including the uploading of a patch artifact for any baseline differences.

Reviewed Changes

Copilot reviewed 13 out of 29 changed files in this pull request and generated 1 comment.

File	Description
testdata/baselines/reference/submodule/conformance/typeOnlyMerge2.js	Removed unused conformance baseline file.
testdata/baselines/reference/submodule/compiler/filesEmittingIntoSameOutput.js	Removed unused compiler baseline file.
testdata/baselines/reference/submodule/compiler/fileReferencesWithNoExtensions.js	Removed unused baseline file for file references.
.github/workflows/ci.yml	Added a new CI job to handle baseline removal, acceptance, and checking.

Files not reviewed (16)

• testdata/baselines/reference/submodule/compiler/fileReferencesWithNoExtensions.js.diff: Language not supported
• testdata/baselines/reference/submodule/compiler/fileReferencesWithNoExtensions.symbols: Language not supported
• testdata/baselines/reference/submodule/compiler/fileReferencesWithNoExtensions.types: Language not supported
• testdata/baselines/reference/submodule/compiler/filesEmittingIntoSameOutput.js.diff: Language not supported
• testdata/baselines/reference/submodule/compiler/filesEmittingIntoSameOutput.symbols: Language not supported
• testdata/baselines/reference/submodule/compiler/filesEmittingIntoSameOutput.types: Language not supported
• testdata/baselines/reference/submodule/compiler/jsFileCompilationWithoutJsExtensions.errors.txt.diff: Language not supported
• testdata/baselines/reference/submodule/conformance/es2022SharedMemory.errors.txt: Language not supported
• testdata/baselines/reference/submodule/conformance/es2022SharedMemory.errors.txt.diff: Language not supported
• testdata/baselines/reference/submodule/conformance/es2022SharedMemory.symbols: Language not supported
• testdata/baselines/reference/submodule/conformance/es2022SharedMemory.symbols.diff: Language not supported
• testdata/baselines/reference/submodule/conformance/es2022SharedMemory.types: Language not supported
• testdata/baselines/reference/submodule/conformance/es2022SharedMemory.types.diff: Language not supported
• testdata/baselines/reference/submodule/conformance/typeOnlyMerge2.errors.txt: Language not supported
• testdata/baselines/reference/submodule/conformance/typeOnlyMerge2.js.diff: Language not supported
• testdata/baselines/reference/submodule/conformance/typeOnlyMerge2.symbols: Language not supported