chore(deps): bump @astrojs/language-server from 2.5.2 to 2.15.4

Bumps [@astrojs/language-server](https://github.com/withastro/language-tools/tree/HEAD/packages/language-server) from 2.5.2 to 2.15.4.
- [Release notes](https://github.com/withastro/language-tools/releases)
- [Changelog](https://github.com/withastro/language-tools/blob/main/packages/language-server/CHANGELOG.md)
- [Commits](https://github.com/withastro/language-tools/commits/@astrojs/[email protected]/packages/language-server)

---
updated-dependencies:
- dependency-name: "@astrojs/language-server"
  dependency-type: indirect
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>