Bump matrix-project from 1.20 to 751.v496d84c0d414

Bumps [matrix-project](https://github.com/jenkinsci/matrix-project-plugin) from 1.20 to 751.v496d84c0d414.
- [Release notes](https://github.com/jenkinsci/matrix-project-plugin/releases)
- [Changelog](https://github.com/jenkinsci/matrix-project-plugin/blob/master/CHANGELOG.md)
- [Commits](https://github.com/jenkinsci/matrix-project-plugin/commits

)

---
updated-dependencies:
- dependency-name: org.jenkins-ci.plugins:matrix-project
  dependency-type: direct:development
...

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