Bump NUnit from 4.2.2 to 4.3.1

Bumps [NUnit](https://github.com/nunit/nunit) from 4.2.2 to 4.3.1.
- [Release notes](https://github.com/nunit/nunit/releases)
- [Changelog](https://github.com/nunit/nunit/blob/main/CHANGES.md)
- [Commits](nunit/nunit@4.2.2...4.3.1)

---
updated-dependencies:
- dependency-name: NUnit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

src/AzureMutex.Tests/packages.lock.json

@@ -24,9 +24,9 @@
       },
       "NUnit": {
         "type": "Direct",
-        "requested": "[4.2.2, )",
-        "resolved": "4.2.2",
-        "contentHash": "mon0OPko28yZ/foVXrhiUvq1LReaGsBdziumyyYGxV/pOE4q92fuYeN+AF+gEU5pCjzykcdBt5l7xobTaiBjsg=="
+        "requested": "[4.3.1, )",
+        "resolved": "4.3.1",
+        "contentHash": "798HDjDWfo2/BVWAeqIny3hRP2z/uk2EVeTeFB69EGHQWxFZ1oVXRaobtOdkzBF4b/olUuWXDJzgtW63aBRDxg=="
       },
       "NUnit3TestAdapter": {
         "type": "Direct",

src/Directory.Packages.props

@@ -8,7 +8,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
-    <PackageVersion Include="NUnit" Version="4.2.2" />
+    <PackageVersion Include="NUnit" Version="4.3.1" />
     <PackageVersion Include="NUnit3TestAdapter" Version="4.6.0" />
   </ItemGroup>
 </Project>