Bump Swashbuckle.AspNetCore (#1852)

Bumps the dotnet group in /docs/extensibility/snippets/MailDevResourceWithCredentials with 1 update: [Swashbuckle.AspNetCore](https://github.com/domaindrivendev/Swashbuckle.AspNetCore).


Updates `Swashbuckle.AspNetCore` from 6.8.1 to 6.9.0
- [Release notes](https://github.com/domaindrivendev/Swashbuckle.AspNetCore/releases)
- [Commits](domaindrivendev/Swashbuckle.AspNetCore@v6.8.1...v6.9.0)

---
updated-dependencies:
- dependency-name: Swashbuckle.AspNetCore
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: dotnet
...

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

docs/extensibility/snippets/MailDevResourceWithCredentials/MailDevResource.NewsletterService/MailDevResource.NewsletterService.csproj

@@ -2,7 +2,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" Version="8.0.10" />
-    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.8.1" />
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.9.0" />
   </ItemGroup>
 
   <ItemGroup>