[v11.0/forgejo] chore: sort mailer messages in test assertion (#8292)

**Backport:** https://codeberg.org/forgejo/forgejo/pulls/8226

- Ref https://codeberg.org/forgejo/forgejo/issues/8221#issuecomment-5461218
- Databases might return users in a different order, sort them before doing assertions on them.

Co-authored-by: Gusted <postmaster@gusted.xyz>
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/8292
Co-authored-by: forgejo-backport-action <forgejo-backport-action@noreply.codeberg.org>
Co-committed-by: forgejo-backport-action <forgejo-backport-action@noreply.codeberg.org>

tests/integration/integration_test.go

@@ -19,6 +19,7 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"slices"
 	"strconv"
 	"strings"
 	"sync/atomic"
@@ -40,6 +41,7 @@ import (
 	"forgejo.org/routers"
 	"forgejo.org/services/auth/source/remote"
 	gitea_context "forgejo.org/services/context"
+	"forgejo.org/services/mailer"
 	user_service "forgejo.org/services/user"
 	"forgejo.org/tests"
 
@@ -691,3 +693,9 @@ func GetHTMLTitle(t testing.TB, session *TestSession, urlStr string) string {
 	doc := NewHTMLParser(t, resp.Body)
 	return doc.Find("head title").Text()
 }
+
+func SortMailerMessages(msgs []*mailer.Message) {
+	slices.SortFunc(msgs, func(a, b *mailer.Message) int {
+		return strings.Compare(b.To, a.To)
+	})
+}