Bump zod from 4.0.14 to 4.0.15 in /.github (#36470)

Bumps [zod](https://github.com/colinhacks/zod) from 4.0.14 to 4.0.15.
- [Release notes](https://github.com/colinhacks/zod/releases)
- [Commits](colinhacks/zod@v4.0.14...v4.0.15)

---
updated-dependencies:
- dependency-name: zod
  dependency-version: 4.0.15
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]