Bump Microsoft.NET.Test.Sdk from 18.8.1 to 18.9.0

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.9.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

tests/BlurHashSharp.ImageSharp.Tests/BlurHashSharp.ImageSharp.Tests.csproj

@@ -8,7 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.8.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.9.0" />
     <PackageReference Include="xunit.v3" Version="3.2.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5" />
     <PackageReference Include="coverlet.collector" Version="10.0.1" />

tests/BlurHashSharp.SkiaSharp.Tests/BlurHashSharp.SkiaSharp.Tests.csproj

@@ -8,7 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.8.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.9.0" />
     <PackageReference Include="xunit.v3" Version="3.2.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5" />
     <PackageReference Include="coverlet.collector" Version="10.0.1" />

tests/BlurHashSharp.Tests/BlurHashSharp.Tests.csproj

@@ -8,7 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.8.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.9.0" />
     <PackageReference Include="xunit.v3" Version="3.2.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5" />
     <PackageReference Include="coverlet.collector" Version="10.0.1" />