chore: bump NuGet.PackageManagement from 6.6.1 to 6.7.0 in /src

Bumps [NuGet.PackageManagement](https://github.com/NuGet/NuGet.Client) from 6.6.1 to 6.7.0.
- [Release notes](https://github.com/NuGet/NuGet.Client/releases)
- [Commits](https://github.com/NuGet/NuGet.Client/commits)

---
updated-dependencies:
- dependency-name: NuGet.PackageManagement
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

src/UnityNuGet/UnityNuGet.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>net7.0</TargetFramework>
@@ -24,7 +24,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Options" Version="7.0.1" />
-    <PackageReference Include="NuGet.PackageManagement" Version="6.6.1" />
+    <PackageReference Include="NuGet.PackageManagement" Version="6.7.0" />
     <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="7.0.0" />
     <PackageReference Include="NUglify" Version="1.20.7" />
     <PackageReference Include="Scriban" Version="5.7.0" />