build(deps): update pytorch-lightning requirement in /requirements

Updates the requirements on [pytorch-lightning](https://github.com/Lightning-AI/lightning) to permit the latest version.
- [Release notes](https://github.com/Lightning-AI/lightning/releases)
- [Commits](Lightning-AI/pytorch-lightning@1.6.0...2.1.0)

---
updated-dependencies:
- dependency-name: pytorch-lightning
  dependency-type: direct:production
...

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

requirements/_integrate.txt

@@ -1,4 +1,4 @@
 # contentiously validated integration with these expected ranges
 
 # ToDo: investigate and add validation with 2.0+ on GPU
-pytorch-lightning >=1.9.0, <2.0.0
+pytorch-lightning >=1.9.0, <3.0.0