fix(metabase): address PR #7253 minor review feedback

- .gitignore: add trailing newline after .mcp.json (POSIX compliance,
  silences "\ No newline at end of file" warnings)
- packages/metabase/tsconfig.json: delete, the package is documentation-only
  (no TS source files, no scripts, no devDependencies) so the config was
  orphaned dead weight

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: maxgfr

.gitignore

@@ -14,4 +14,4 @@ packages/code-du-travail-modeles/bin
 packages/code-du-travail-modeles/lib
 token
 .lighthouseci
-.mcp.json
+.mcp.json