Bump torch from 1.7.0 to 2.2.0 in /fastmri_examples/adaptive_varnet

Bumps [torch](https://github.com/pytorch/pytorch) from 1.7.0 to 2.2.0.
- [Release notes](https://github.com/pytorch/pytorch/releases)
- [Changelog](https://github.com/pytorch/pytorch/blob/main/RELEASE.md)
- [Commits](pytorch/pytorch@v1.7.0...v2.2.0)

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

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

fastmri_examples/adaptive_varnet/requirements.txt

@@ -1,7 +1,7 @@
 numpy==1.18.5
 scikit_image==0.16.2
 torchvision==0.8.1
-torch==1.7.0
+torch==2.2.0
 runstats==2.0.0
 pytorch_lightning==1.0.6
 h5py==2.10.0