chore(deps): bump jenkins/ssh-agent in /dockerfiles/maven (#1536)

Bumps jenkins/ssh-agent from 6.24.0-jdk21 to 7.0.0-jdk21.

---
updated-dependencies:
- dependency-name: jenkins/ssh-agent
  dependency-version: 7.0.0-jdk21
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]