chore: ignore __pycache__, which the checker generates on every run

scripts/check-comment-runs.py is Python, so running it leaves
scripts/__pycache__/*.pyc — interpreter-version-specific bytecode that a wave
agent then committed, because nothing ignored it. Found by review on PR #41.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.gitignore

@@ -53,3 +53,7 @@ GSYMS
 /graph.html
 /graph.svg
 .human
+
+# Python bytecode from scripts/ (interpreter-version-specific, regenerated)
+__pycache__/
+*.pyc