build(deps): bump symfony/polyfill-php73 from 1.29.0 to 1.31.0

Bumps [symfony/polyfill-php73](https://github.com/symfony/polyfill-php73) from 1.29.0 to 1.31.0.
- [Commits](symfony/polyfill-php73@v1.29.0...v1.31.0)

---
updated-dependencies:
- dependency-name: symfony/polyfill-php73
  dependency-type: indirect
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>