fix(websocket): set rootDir in tsconfig.json for TypeScript 6 compatibility

TypeScript 6 (TS5011) requires rootDir to be explicitly set when the
common source directory doesn't match the project root. Set rootDir
to "src" to match the include pattern and fix the build failure.

Co-Authored-By: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>