docs: document that ServiceProvider.Dispose() throws for async-only disposables, recommend DisposeAsync()

src/libraries/Microsoft.Extensions.DependencyInjection/src/ServiceProvider.cs

@@ -169,14 +169,26 @@ internal object GetRequiredKeyedService(Type serviceType, object? serviceKey, Se
 
         internal bool IsDisposed() => _disposed;
 
-        /// <inheritdoc />
+        /// <summary>
+        /// Disposes the service provider and all resolved services that implement <see cref="IDisposable"/>.
+        /// </summary>
+        /// <remarks>
+        /// Prefer calling <see cref="DisposeAsync"/> over this method. If any resolved service implements
+        /// <see cref="IAsyncDisposable"/> but not <see cref="IDisposable"/>, this method throws an
+        /// <see cref="InvalidOperationException"/>. Use <see cref="DisposeAsync"/> to properly handle all
+        /// disposable services, or explicitly perform sync-over-async on the caller side if synchronous
+        /// disposal is required.
+        /// </remarks>
         public void Dispose()
         {
             DisposeCore();
             Root.Dispose();
         }
 
-        /// <inheritdoc/>
+        /// <summary>
+        /// Asynchronously disposes the service provider and all resolved services that implement <see cref="IDisposable"/> or <see cref="IAsyncDisposable"/>.
+        /// </summary>
+        /// <returns>A value task that represents the asynchronous operation.</returns>
         public ValueTask DisposeAsync()
         {
             DisposeCore();