Bump Microsoft.NET.Test.Sdk from 17.14.1 to 18.0.0 (#219)

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

test/SimpleAPI.Tests/SimpleAPI.Tests.csproj

@@ -20,7 +20,7 @@
     <PackageReference Include="Amazon.Lambda.TestUtilities" Version="3.0.1" />
     <PackageReference Include="Amazon.Lambda.APIGatewayEvents" Version="2.7.1" />
     <PackageReference Include="AWSSDK.Extensions.NETCore.Setup" Version="4.0.3.4" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.0.0" />
     <PackageReference Include="xunit" Version="2.9.3" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5" />
   </ItemGroup>