Minor fuzzer improvements (#9375)
<!--
Thank you for contributing to Ruff! To help us out with reviewing,
please consider the following:
- Does this pull request include a summary of the change? (See below.)
- Does this pull request include a descriptive title?
- Does this pull request include references to any relevant issues?
-->
## Summary
- Adds timeouts to fuzzer cmin stages in the case of an infinite loop
- Adds executable flag to reinit-fuzzer.sh because it was annoying me
## Test Plan
Not needed.
