build(deps): bump pyspark from 3.5.3 to 3.5.6 in /runtimes/mllib (#2169)

Bumps [pyspark](https://github.com/apache/spark) from 3.5.3 to 3.5.6.
- [Commits](apache/spark@v3.5.3...v3.5.6)

---
updated-dependencies:
- dependency-name: pyspark
  dependency-version: 3.5.6
  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]