* Fix Lean4 stale cache: skip caching empty document symbol responses
When the Lean language server is queried before `lake build` completes,
it returns empty symbol lists. Previously these were written to the
persistent cache, permanently hiding symbols even after the build
finished. Now only non-empty responses are cached.
Adds a unit test that verifies empty responses from the LSP layer are
never written to _raw_document_symbols_cache.
Fixes#1217
* fix: run poe format and add changelog entry for #1356
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---------
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: Michael Panchenko <35432522+MischaPanch@users.noreply.github.com>
Black dependency created a dependabot warning and couldn't be bumped since it collided with pathspec dependencies. Since ruff can also format, black is not needed. But we now have these small format changes, mostly in test files
Dominik Jain