fix: Re-add least recently updated as sort order

Regression from https://codeberg.org/forgejo/forgejo/pulls/5819
Integration test added (my first! 🎉)

tests/integration/repo_test.go

@@ -1048,6 +1048,42 @@ func TestFileHistoryPager(t *testing.T) {
 	})
 }
 
+func TestRepoIssueSorting(t *testing.T) {
+	defer tests.PrepareTestEnv(t)()
+
+	t.Run("Dropdown content", func(t *testing.T) {
+		defer tests.PrintCurrentTest(t)()
+
+		req := NewRequest(t, "GET", "/user2/repo1/issues")
+		resp := MakeRequest(t, req, http.StatusOK)
+		htmlDoc := NewHTMLParser(t, resp.Body)
+
+		assert.Equal(t,
+			9,
+			htmlDoc.Find(`.list-header-sort .menu a`).Length(),
+			"Wrong amount of sort options in dropdown")
+
+		menuItemsHTML := htmlDoc.Find(`.list-header-sort .menu`).Text()
+		locale := translation.NewLocale("en-US")
+		for _, key := range []string{
+			"relevance",
+			"latest",
+			"oldest",
+			"recentupdate",
+			"leastupdate",
+			"mostcomment",
+			"leastcomment",
+			"nearduedate",
+			"farduedate",
+		} {
+			assert.Contains(t,
+				menuItemsHTML,
+				locale.Tr("repo.issues.filter_sort."+key),
+				"Sort option %s ('%s') not found in dropdown", key, locale.Tr("repo.issues.filter_sort."+key))
+		}
+	})
+}
+
 func TestRepoIssueFilterLinks(t *testing.T) {
 	defer tests.PrepareTestEnv(t)()