Add release notes for Seq.empty serialization fix

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: apoorvdarshan

docs/release-notes/.FSharp.Core/10.0.300.md

@@ -6,6 +6,7 @@
 * Fix tuple/multi-value projections in queries to use Queryable.Select instead of Enumerable.Select when the source is IQueryable, preserving query composition and enabling async operations like ToListAsync() in Entity Framework Core. ([Issue #3782](https://github.com/dotnet/fsharp/issues/3782), [Issue #15133](https://github.com/dotnet/fsharp/issues/15133))
 * Fix EvaluateQuotation to handle Sequential expressions, void method calls (unit return), and other patterns that were previously throwing NotSupportedException. Also properly handles unit-returning expressions by using Action delegates instead of Func delegates. ([Issue #19099](https://github.com/dotnet/fsharp/issues/19099))
 * Fix query conditionals without else branch (if-then only) that were causing type mismatch errors. Now properly extracts element type from IQueryable for creating empty sequences. ([Issue #3445](https://github.com/dotnet/fsharp/issues/3445))
+* Fix `Seq.empty` rendering as `"EmptyEnumerable"` in serializers by delegating to `System.Linq.Enumerable.Empty<'T>()` instead of using a custom DU type. ([Issue #17864](https://github.com/dotnet/fsharp/issues/17864), [PR #19317](https://github.com/dotnet/fsharp/pull/19317))
 
 ### Added