add bzip2 package (#28)

Static build of bzip2 1.0.8 (libbz2.a + bzlib.h) for use as a
vendored dependency in openpilot replay/cabana tools.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

pyproject.toml

@@ -1,5 +1,6 @@
 [tool.uv.workspace]
 members = [
+  "bzip2",
   "capnproto",
   "cppcheck",
   "eigen",