Bump etc/coq-scripts from 857071d to e4d9e81 (mit-plv#1896)

Bumps [etc/coq-scripts](https://github.com/JasonGross/coq-scripts) from `857071d` to `e4d9e81`.
- [Commits](JasonGross/coq-scripts@857071d...e4d9e81)

---
updated-dependencies:
- dependency-name: etc/coq-scripts
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>