Update azure-mgmt-network requirement from ~=28.0.0 to ~=28.1.0

Updates the requirements on [azure-mgmt-network](https://github.com/Azure/azure-sdk-for-python) to permit the latest version.
- [Release notes](https://github.com/Azure/azure-sdk-for-python/releases)
- [Changelog](https://github.com/Azure/azure-sdk-for-python/blob/main/doc/esrp_release.md)
- [Commits](Azure/azure-sdk-for-python@azure-mgmt-network_28.0.0...azure-mgmt-network_28.1.0)

---
updated-dependencies:
- dependency-name: azure-mgmt-network
  dependency-type: direct:production
...

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

requirements.txt

@@ -1,7 +1,7 @@
 azure-identity~=1.19.0
 azure-mgmt-compute~=33.1.0
 azure-mgmt-monitor~=6.0.2
-azure-mgmt-network~=28.0.0
+azure-mgmt-network~=28.1.0
 azure-mgmt-resource~=23.2.0
 azure-mgmt-storage~=21.2.1
 azure-monitor-query~=1.4.0