Fix FastFetch MicroBuild signing for NativeAOT publish

With PublishAot=true, dotnet publish produces the native executable in
$(PublishDir) rather than $(OutputPath). The FilesToSign items were
still referencing $(OutputPath)\FastFetch.exe, causing the ESRP
signing task to fail because the file doesn't exist at that path.

Change the signing path to $(PublishDir) and remove the managed DLL
entries (GVFS.Common.dll, GVFS.Platform.Windows.dll,
GVFS.Virtualization.dll) which are statically linked into the native
AOT binary and no longer exist as separate files.

Assisted-by: Claude Opus 4.6
Signed-off-by: Tyler Vella <tyrielv@gmail.com>

Author: tyrielv

GVFS/FastFetch/FastFetch.csproj

@@ -16,11 +16,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <FilesToSign Include="
-      $(OutputPath)\FastFetch.exe;
-      $(OutputPath)\GVFS.Common.dll;
-      $(OutputPath)\GVFS.Platform.Windows.dll;
-      $(OutputPath)\GVFS.Virtualization.dll;">
+    <FilesToSign Include="$(PublishDir)\FastFetch.exe">
       <Authenticode>Microsoft400</Authenticode>
       <InProject>false</InProject>
     </FilesToSign>