Bump NuGet.Protocol from 6.11.1 to 6.12.1 in /src (#2631)

Bumps [NuGet.Protocol](https://github.com/NuGet/NuGet.Client) from 6.11.1 to 6.12.1.
- [Release notes](https://github.com/NuGet/NuGet.Client/releases)
- [Commits](https://github.com/NuGet/NuGet.Client/commits)

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

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

src/Core/efcpt.6/efcpt.6.csproj

@@ -54,7 +54,7 @@
     <PackageReference Include="Ben.Demystifier" Version="0.4.1" />
     <PackageReference Include="CommandLineParser" Version="2.9.1" />
     <PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.1" />
-    <PackageReference Include="NuGet.Protocol" Version="6.11.1" />
+    <PackageReference Include="NuGet.Protocol" Version="6.12.1" />
     <PackageReference Include="Spectre.Console" Version="0.49.1" />
     <PackageReference Include="System.IO.Abstractions" Version="21.1.3" />
   </ItemGroup>

src/Core/efcpt.8/efcpt.8.csproj

@@ -47,7 +47,7 @@
     <PackageReference Include="Ben.Demystifier" Version="0.4.1" />
     <PackageReference Include="CommandLineParser" Version="2.9.1" />
     <PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.1" />
-    <PackageReference Include="NuGet.Protocol" Version="6.11.1" />
+    <PackageReference Include="NuGet.Protocol" Version="6.12.1" />
     <PackageReference Include="Spectre.Console" Version="0.49.1" />
     <PackageReference Include="System.IO.Abstractions" Version="21.1.3" />
   </ItemGroup>

src/Core/efcpt.9/efcpt.9.csproj

@@ -57,7 +57,7 @@
     <PackageReference Include="Ben.Demystifier" Version="0.4.1" />
     <PackageReference Include="CommandLineParser" Version="2.9.1" />
     <PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.1" />
-    <PackageReference Include="NuGet.Protocol" Version="6.11.1" />
+    <PackageReference Include="NuGet.Protocol" Version="6.12.1" />
     <PackageReference Include="Spectre.Console" Version="0.49.1" />
     <PackageReference Include="System.IO.Abstractions" Version="21.1.3" />
   </ItemGroup>