* Resolve npm install warning for @types/diff deprecation

> npm warn deprecated @types/diff@8.0.0: This is a stub types definition. diff provides its own type definitions, so you do not need this installed.

Related: #1828

* Migrates away from unmaintained npm package fantasticon

Replaces with @twbs/fantasticon fork, which is maintained.

Tested by running `npm run compile-icons` (which is indirectly
included in the `postinstall` script too), and then previewing
the built font (assets/icons/icon-font.woff) on
https://fontdrop.info. The 3 expected glyphs were present at
the expected codepoints.

This does NOT resolve the npm install warning I initially was
pursuring. The transitive dep chain is deep, and @twbs/fantasticon
still contains the deprecated version of @npmcli/move-file.

> npm warn deprecated @npmcli/move-file@2.0.1: This functionality has been moved to @npmcli/fs

* Add dynamic local schema detection for SourceKit-LSP

Implement support for using local schema files from the Swift toolchain
when available, with automatic fallback to remote GitHub schemas for
older toolchains.

This enables the extension to use the accurate schema for the users
toolchain, if its present, while maintaining backward compatibility
with older toolchains.

* Normalize paths in tests

* Update CHANGELOG

Clean up the codebase so that it uses the built in
`vscode.Disposable.from` to dispose multiple disposables at the same
time. This replaces our own `compositeDisposable` method.

Docs here: https://code.visualstudio.com/api/references/vscode-api#Disposable

Bumps the all-dependencies group with 2 updates: [prettier](https://github.com/prettier/prettier) and [tsx](https://github.com/privatenumber/tsx).


Updates `prettier` from 3.6.2 to 3.7.3
- [Release notes](https://github.com/prettier/prettier/releases)
- [Changelog](https://github.com/prettier/prettier/blob/main/CHANGELOG.md)
- [Commits](prettier/prettier@3.6.2...3.7.3)

Updates `tsx` from 4.20.6 to 4.21.0
- [Release notes](https://github.com/privatenumber/tsx/releases)
- [Changelog](https://github.com/privatenumber/tsx/blob/master/release.config.cjs)
- [Commits](privatenumber/tsx@v4.20.6...v4.21.0)

---
updated-dependencies:
- dependency-name: prettier
  dependency-version: 3.7.3
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: all-dependencies
- dependency-name: tsx
  dependency-version: 4.21.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: all-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

* Add Playgrounds to the project panel

- Support `workspace/playgrounds` request, persisting the playgrounds in
  memory and listening for new "swift.play" CodeLens to keep up to date
- Display the list of playgrounds in the project panel
- Clicking on playground in the project panel will open its location
- Provide a play option

Issue: #1782

* Better error handling and only fetch if workspace/playground is experimental capability

* Context command to run playground

* Add test

* Fix failing unit test

* Fix review comments