Bump Microsoft.NET.Test.Sdk from 16.8.3 to 16.9.1

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 16.8.3 to 16.9.1.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Commits](microsoft/vstest@v16.8.3...v16.9.1)

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

src/Stravaig.FamilyTree.Standardiser.UnitTests/Stravaig.FamilyTree.Standardiser.UnitTests.csproj

@@ -7,9 +7,9 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="nunit" Version="3.13.0" />
+        <PackageReference Include="nunit" Version="3.13.1" />
         <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.1" />
         <PackageReference Include="Shouldly" Version="4.0.3" />
     </ItemGroup>
 

src/Stravaig.FamilyTreeGenerator.Tests/Stravaig.FamilyTreeGenerator.Tests.csproj

@@ -7,9 +7,9 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="nunit" Version="3.13.0" />
+        <PackageReference Include="nunit" Version="3.13.1" />
         <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.1" />
     </ItemGroup>
 
     <ItemGroup>

src/Stravaig.Gedcom.UnitTests/Stravaig.Gedcom.UnitTests.csproj

@@ -8,9 +8,9 @@
     </PropertyGroup>
 
     <ItemGroup>
-        <PackageReference Include="nunit" Version="3.13.0" />
+        <PackageReference Include="nunit" Version="3.13.1" />
         <PackageReference Include="NUnit3TestAdapter" Version="3.17.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.8.3" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.9.1" />
         <PackageReference Include="Shouldly" Version="4.0.3" />
     </ItemGroup>