Bump Microsoft.NET.Test.Sdk from 18.7.0 to 18.8.0

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.8.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

src/CookieSample.E2ETests/CookieSample.E2ETests.csproj

@@ -7,7 +7,7 @@
 
   <ItemGroup>
     <PackageReference Include="ClosedXML" Version="0.105.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.7.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.8.0" />
     <PackageReference Include="Selenium.WebDriver" Version="4.46.0" />
     <PackageReference Include="Selenium.WebDriver.ChromeDriver" Version="150.0.7871.11500" />
     <PackageReference Include="Selenium.WebDriver.MSEdgeDriver" Version="126.0.2592.102" Condition=" '$(OS)' == 'Windows_NT' " />