summarize_stats.py script should output error, not fail, if denominator is unexpectedly 0

[mdboom]

Bug report

Bug description:

The summarize_stats.py script will currently throw an exception if a ratio has a non-zero numerator over a zero denominator. While this is an error, it would be better to output this error to the output markdown rather than hard fail.

CPython versions tested on:

CPython main branch

Operating systems tested on:

Linux

Linked PRs

• gh-111277: In summarize_stats.py, don't fail fast on invalid ratios #111278