Merge branch 'mr/botcazou-gnat#1696' into 'main'

Work around an illegal Ada 2012 construct now spotted by the compiler

See merge request eng/shared/vss-text!14

Author: Eric Botcazou

source/text/implementation/vss-strings-cursors-iterators-characters.adb

@@ -4,6 +4,8 @@
 --  SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 --
 
+pragma Ada_2022;
+
 package body VSS.Strings.Cursors.Iterators.Characters is
 
    use type VSS.Implementation.Referrers.Magic_String_Access;