.NET: Add RequiresDynamicCode to ITextSearch<TRecord> interface methods

Fixes IL3051 compilation errors by adding RequiresDynamicCode attributes to:
- SearchAsync(string, TextSearchOptions<TRecord>?, CancellationToken)
- GetTextSearchResultsAsync(string, TextSearchOptions<TRecord>?, CancellationToken)
- GetSearchResultsAsync(string, TextSearchOptions<TRecord>?, CancellationToken)

The generic ITextSearch<TRecord> interface accepts LINQ expressions via
TextSearchOptions<TRecord>.Filter, which requires dynamic code generation
for expression tree processing. This change ensures interface methods
match their implementations' RequiresDynamicCode attributes.

Resolves: Issue #10456 IL3051 interface mismatch errors
Cherry-pick-safe: Interface-only change, no implementation logic

Author: alzarei

dotnet/src/SemanticKernel.Abstractions/Data/TextSearch/ITextSearch.cs

@@ -19,6 +19,7 @@ public interface ITextSearch<TRecord>
     /// <param name="query">What to search for.</param>
     /// <param name="searchOptions">Options used when executing a text search.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
+    [RequiresDynamicCode("LINQ filtering over generic types requires dynamic code generation for expression trees.")]
     Task<KernelSearchResults<string>> SearchAsync(
         string query,
         TextSearchOptions<TRecord>? searchOptions = null,
@@ -30,6 +31,7 @@ Task<KernelSearchResults<string>> SearchAsync(
     /// <param name="query">What to search for.</param>
     /// <param name="searchOptions">Options used when executing a text search.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
+    [RequiresDynamicCode("LINQ filtering over generic types requires dynamic code generation for expression trees.")]
     Task<KernelSearchResults<TextSearchResult>> GetTextSearchResultsAsync(
         string query,
         TextSearchOptions<TRecord>? searchOptions = null,
@@ -41,6 +43,7 @@ Task<KernelSearchResults<TextSearchResult>> GetTextSearchResultsAsync(
     /// <param name="query">What to search for.</param>
     /// <param name="searchOptions">Options used when executing a text search.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
+    [RequiresDynamicCode("LINQ filtering over generic types requires dynamic code generation for expression trees.")]
     Task<KernelSearchResults<object>> GetSearchResultsAsync(
         string query,
         TextSearchOptions<TRecord>? searchOptions = null,