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>

bzip2/bzip2/__init__.py

@@ -0,0 +1,10 @@
+import os
+
+DIR = os.path.join(os.path.dirname(__file__), "install")
+LIB_DIR = os.path.join(DIR, "lib")
+INCLUDE_DIR = os.path.join(DIR, "include")
+
+
+def smoketest():
+  assert os.path.isfile(os.path.join(LIB_DIR, "libbz2.a")), "libbz2.a not found"
+  assert os.path.isfile(os.path.join(INCLUDE_DIR, "bzlib.h")), "bzlib.h not found"