Bump Verify.Nunit from 26.2.0 to 26.3.1 in /src

Bumps [Verify.Nunit](https://github.com/VerifyTests/Verify) from 26.2.0 to 26.3.1.
- [Release notes](https://github.com/VerifyTests/Verify/releases)
- [Commits](VerifyTests/Verify@26.2.0...26.3.1)

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

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

src/Directory.Packages.props

@@ -17,7 +17,7 @@
     <PackageVersion Include="ProjectDefaults" Version="1.0.135" />
     <PackageVersion Include="PropertyChanged.Fody" Version="4.1.0" />
     <PackageVersion Include="System.Runtime.InteropServices.RuntimeInformation" Version="4.3.0" />
-    <PackageVersion Include="Verify.NUnit" Version="26.2.0" />
+    <PackageVersion Include="Verify.NUnit" Version="26.3.1" />
     <PackageVersion Include="Xamarin.Essentials" Version="1.8.0" />
     <PackageVersion Include="Xamarin.Google.Android.Material" Version="1.10.0.1" />
   </ItemGroup>