feat: add same_site = none_secure option

c.f. https://web.dev/samesite-cookies-explained/
diff --git a/src/couch/src/couch_httpd_auth.erl b/src/couch/src/couch_httpd_auth.erl
index 45a82bd..9d82e2d 100644
--- a/src/couch/src/couch_httpd_auth.erl
+++ b/src/couch/src/couch_httpd_auth.erl
@@ -497,6 +497,7 @@
     case string:to_lower(SameSite) of
         "" -> [];
         "none" -> [{same_site, none}];
+        "none_secure" -> [{same_site, none}, secure];
         "lax" -> [{same_site, lax}];
         "strict" -> [{same_site, strict}];
         _ ->