Update bug_report.md

[trendvidia]

Summary

What this PR changes, in 1–3 sentences.

Why

Link to the issue or upstream spec/codec change that motivated this.

Scope

• FFI boundary (src/_protowire/)
• Public Python API (src/protowire/)
• Tests / fixtures / harnesses (tests/, testdata/, scripts/)
• Build / packaging / CI (pyproject.toml, CMakeLists.txt, .github/)
• Documentation only

Test plan

• Local build clean: pip install -e '.[test]' && pytest
• If FFI-boundary change: round-tripped at least one PXF + SBE fixture
  against the sibling protowire-cpp checkout
• If wire-impacting: matching upstream PRs linked above
• If new public symbol: exported from protowire/__init__.py and
  covered by a test under tests/
• If packaging change: cibuildwheel matrix smoke build still passes