build(deps-dev): bump torchmetrics in /runtimes/mlflow

Bumps [torchmetrics](https://github.com/Lightning-AI/torchmetrics) from 1.6.1 to 1.6.3.
- [Release notes](https://github.com/Lightning-AI/torchmetrics/releases)
- [Changelog](https://github.com/Lightning-AI/torchmetrics/blob/master/CHANGELOG.md)
- [Commits](Lightning-AI/torchmetrics@v1.6.1...v1.6.3)

---
updated-dependencies:
- dependency-name: torchmetrics
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

runtimes/mlflow/poetry.lock

@@ -16,7 +16,7 @@ mlflow = "*"
 mlserver = {path = "../..", develop = true}
 torch = "^2.4"
 pytorch-lightning = "^2.4"
-torchmetrics = "1.6.1"
+torchmetrics = "1.6.3"
 torchvision = "0.19.1"
 
 [build-system]