[DOCS] EQL: Fix delete async EQL search snippet (#75093)

The delete async EQL search API doesn't support the `keep_alive` query parameter.

docs/reference/eql/eql.asciidoc

@@ -732,7 +732,7 @@ search is still ongoing, {es} cancels the search request.
 
 [source,console]
 ----
-DELETE /_eql/search/FmNJRUZ1YWZCU3dHY1BIOUhaenVSRkEaaXFlZ3h4c1RTWFNocDdnY2FSaERnUTozNDE=?keep_alive=5d
+DELETE /_eql/search/FmNJRUZ1YWZCU3dHY1BIOUhaenVSRkEaaXFlZ3h4c1RTWFNocDdnY2FSaERnUTozNDE=
 ----
 // TEST[skip: no access to search ID]