Update pytorch-lightning requirement

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@1.8.0...2.1.0)

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

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

pyproject.toml

@@ -25,7 +25,7 @@ dependencies = [
     "jsonlines",
     "loguru",
     "pydantic",
-    "pytorch-lightning >= 1.8.0, < 2.1.0",
+    "pytorch-lightning >= 1.8.0, < 2.2.0",
     "rich",
     "sacrebleu",
     "sacremoses",