emacs-29 64a2b0d36fe: Fix failure of fns-tests-collate-strings on Cygwin

[Ken Brown]

branch: emacs-29
commit 64a2b0d36fe9152641fe2017d36d5fc4ee2b7fc6
Author: Ken Brown <kbrown@cornell.edu>
Commit: Ken Brown <kbrown@cornell.edu>

    Fix failure of fns-tests-collate-strings on Cygwin
    
    * test/src/fns-tests.el (fns-tests-collate-strings): Use
    en_XY.UTF-8 instead of en_DE.UTF-8 as an example of an invalid
    locale; en_DE.UTF-8 is actually a valid locale on Cygwin.
    Note: The test will still fail on Cygwin releases < 3.5
    because of a Cygwin bug.  (Bug#62420)
---
 test/src/fns-tests.el | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/src/fns-tests.el b/test/src/fns-tests.el
index e0d6c96b360..c36b5e3f41b 100644
--- a/test/src/fns-tests.el
+++ b/test/src/fns-tests.el
@@ -253,8 +253,8 @@
   ;; Ignore case.
   (should (string-collate-equalp "xyzzy" "XYZZY" nil t))
 
-  ;; Locale must be valid.
-  (should-error (string-collate-equalp "xyzzy" "xyzzy" "en_DE.UTF-8")))
+  ;; Locale must be valid.  This test will fail on Cygwin releases < 3.5.
+  (should-error (string-collate-equalp "xyzzy" "xyzzy" "en_XY.UTF-8")))
 
 ;; There must be a check for valid codepoints.  (Check not implemented yet)
 ;  (should-error