Bump luigi from 3.4.0 to 3.6.0 in /luigi_pipeline

Bumps [luigi](https://github.com/spotify/luigi) from 3.4.0 to 3.6.0.
- [Release notes](https://github.com/spotify/luigi/releases)
- [Changelog](https://github.com/spotify/luigi/blob/master/RELEASE-PROCESS.rst)
- [Commits](spotify/luigi@3.4.0...v3.6.0)

---
updated-dependencies:
- dependency-name: luigi
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

luigi_pipeline/requirements.txt

@@ -1,4 +1,4 @@
 elasticsearch==7.9.1
 hail>=0.2.113
-luigi==3.4.0
+luigi==3.6.0
 google-api-python-client>=1.8.0