fix: remove unused SQLite native asset warning in TodoApp.BlazorWasm.Client (#560)

CommunityToolkit.Datasync.Client depends unconditionally on
Microsoft.EntityFrameworkCore.Sqlite, which transitively adds a
browser-wasm NativeFileReference for SourceGear.sqlite3's e_sqlite3.a
via SQLitePCLRaw.bundle_e_sqlite3 (pinned in this project only to
resolve NU1903, see #492). This client never uses SQLite/
OfflineDbContext (verified: no references to DbContext, Sqlite, or
OfflineTable anywhere in the project), so the native asset is dead
weight and trips a benign, code-less warning from the SDK's
WorkloadManifest.targets:

  warning : @(NativeFileReference) is not empty, but the native
  references won't be linked in, because neither $(WasmBuildNative),
  nor $(RunAOTCompilation) are 'true'.

Root cause traced to SourceGear.sqlite3's buildTransitive targets,
which unconditionally add the native asset whenever
$(RuntimeIdentifier) == 'browser-wasm', independent of which
SQLitePCLRaw.bundle_e_sqlite3 version resolves. Since the warning has
no diagnostic code it can't be suppressed via NoWarn, so instead
remove the specific unused NativeFileReference item before the SDK's
_CheckBrowserWorkloadNeededButNotAvailable target runs.

Verified locally (dotnet restore + build
samples/todoapp-blazor-wasm/TodoApp.BlazorWasm.sln, matching
build-samples-todoapp-blazor-wasm.yml): warning present twice in a
clean build before this change, zero occurrences after, with an
otherwise identical Debug build (0 Warning(s), 0 Error(s)). Also
verified the root Datasync.Toolkit.sln still restores/builds clean and
CommunityToolkit.Datasync.Client.Test passes 1432/1432 (unaffected by
this samples-only change, but confirms no regression).

Fixes #523

Co-authored-by: ahall <ahall@cloudflare.com>

Author: adrianhall

samples/todoapp-blazor-wasm/TodoApp.BlazorWasm.Client/TodoApp.BlazorWasm.Client.csproj

@@ -19,4 +19,18 @@
     <ProjectReference Include="..\TodoApp.BlazorWasm.Shared\TodoApp.BlazorWasm.Shared.csproj" />
   </ItemGroup>
 
+  <!--
+    CommunityToolkit.Datasync.Client depends unconditionally on Microsoft.EntityFrameworkCore.Sqlite,
+    which transitively adds a browser-wasm NativeFileReference for SourceGear.sqlite3's e_sqlite3.a
+    (via SQLitePCLRaw.bundle_e_sqlite3, pinned above only to resolve NU1903 - see #492). This app never
+    uses SQLite/OfflineDbContext, so the native asset is unused; remove it before the SDK's browser
+    workload check runs to avoid a benign, code-less "NativeFileReference is not empty..." warning
+    from WorkloadManifest.targets. See #523.
+  -->
+  <Target Name="RemoveUnusedSqliteNativeFileReference" BeforeTargets="_CheckBrowserWorkloadNeededButNotAvailable">
+    <ItemGroup>
+      <NativeFileReference Remove="@(NativeFileReference)" Condition="'%(Filename)%(Extension)' == 'e_sqlite3.a'" />
+    </ItemGroup>
+  </Target>
+
 </Project>