Bump azure-mgmt-resource from 20.0.0 to 21.1.0

Bumps [azure-mgmt-resource](https://github.com/Azure/azure-sdk-for-python) from 20.0.0 to 21.1.0.
- [Release notes](https://github.com/Azure/azure-sdk-for-python/releases)
- [Commits](Azure/azure-sdk-for-python@azure-mgmt-resource_20.0.0...azure-mgmt-resource_21.1.0)

---
updated-dependencies:
- dependency-name: azure-mgmt-resource
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements.txt

@@ -21,7 +21,7 @@ python-dateutil==2.8.2
 pid==3.0.4
 azure-mgmt-compute==27.1.0
 azure-mgmt-storage==20.0.0
-azure-mgmt-resource==20.0.0
+azure-mgmt-resource==21.1.0
 azure-keyvault-secrets==4.3.0
 azure-storage-blob==12.12.0
 sockjs==0.11.0