Update torchmetrics requirement in /_requirements

Updates the requirements on [torchmetrics](https://github.com/Lightning-AI/torchmetrics) to permit the latest version.
- [Release notes](https://github.com/Lightning-AI/torchmetrics/releases)
- [Changelog](https://github.com/Lightning-AI/torchmetrics/blob/master/CHANGELOG.md)
- [Commits](Lightning-AI/torchmetrics@v0.7.0...v1.2.0)

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

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

_requirements/default.txt

@@ -4,4 +4,4 @@ ipython[notebook]>=8.0.0, <8.15.0
 urllib3  # for ipython
 torch>=1.8.1, <2.1.0
 pytorch-lightning>=1.4, <2.1.0
-torchmetrics>=0.7, <1.2
+torchmetrics>=0.7, <1.3