doc/go1.21: merge x/exp/slices issue into slices package

For #57348

Change-Id: I84943711b033d63f0993133f93d9f09ce2af5965
Reviewed-on: https://go-review.googlesource.com/c/go/+/498395
Reviewed-by: Eli Bendersky <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Run-TryBot: Ian Lance Taylor <[email protected]>
Reviewed-by: Matthew Dempsky <[email protected]>
Auto-Submit: Ian Lance Taylor <[email protected]>

Author: ianlancetaylor

doc/go1.21.html

@@ -195,7 +195,7 @@ <h3 id="slog">New log/slog package</h3>
 
 <h3 id="slices">New slices package</h3>
 
-<p><!-- https://go.dev/issue/45955, https://go.dev/issue/54768, https://go.dev/issue/57433, CL 467417, CL 483175 -->
+<p><!-- https://go.dev/issue/45955, https://go.dev/issue/54768, https://go.dev/issue/57348, https://go.dev/issue/57433, CL 467417, CL 483175 -->
   The new <a href="/pkg/slices">slices</a> package provides many common
   operations on slices, using generic functions that work with slices
   of any element type.
@@ -781,14 +781,6 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
   </dd>
 </dl><!-- testing/slogtest -->
 
-<dl id="x/exp/slices"><dt><a href="/pkg/x/exp/slices/">x/exp/slices</a></dt>
-  <dd>
-    <p><!-- https://go.dev/issue/57348 -->
-      TODO: <a href="https://go.dev/issue/57348">https://go.dev/issue/57348</a>: Allow different types for haystack/needle in BinarySearchFunc
-    </p>
-  </dd>
-</dl><!-- x/exp/slices -->
-
 <dl id="x/sys/windows"><dt><a href="/pkg/x/sys/windows/">x/sys/windows</a></dt>
   <dd>
     <p><!-- https://go.dev/issue/54232 -->