build(deps): bump Swashbuckle.AspNetCore in /sample-api/api

Bumps [Swashbuckle.AspNetCore](https://github.com/domaindrivendev/Swashbuckle.AspNetCore) from 6.7.1 to 6.7.3.
- [Release notes](https://github.com/domaindrivendev/Swashbuckle.AspNetCore/releases)
- [Commits](https://github.com/domaindrivendev/Swashbuckle.AspNetCore/compare/v6.7.1...v6.7.3)

---
updated-dependencies:
- dependency-name: Swashbuckle.AspNetCore
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

sample-api/api/src/ToDoApi.csproj

@@ -10,7 +10,7 @@
     <PackageReference Include="Microsoft.Identity.Web" Version="3.1.0" />
     <PackageReference Include="Microsoft.OData.Core" Version="8.0.1" />
     <PackageReference Include="Microsoft.OpenApi.OData" Version="1.6.8" />
-    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.7.1" />
+    <PackageReference Include="Swashbuckle.AspNetCore" Version="6.7.3" />
   </ItemGroup>
   <ItemGroup>
     <InternalsVisibleTo Include="ToDoApi.Tests" />