fix(pull): respect max approvers in default merge message (#40118) (#40119)

Backport #40118 by @lazerg

The approver limit was checked before writing each `Reviewed-by:` line
but compared with `>`, so the default merge message got one more trailer
than `DEFAULT_MERGE_MESSAGE_MAX_APPROVERS` allows (2 with a limit of 1,
11 with the default 10). It now stops once the limit is reached.

Fixes https://github.com/go-gitea/gitea/issues/40116

Assisted-by: Claude Code:claude-opus-5-5

Co-authored-by: Lazizbek Ergashev <lazerg2@gmail.com>

models/issues/pull.go

@@ -378,7 +378,7 @@ func (pr *PullRequest) getReviewedByLines(ctx context.Context, writer io.Writer)
 	reviewersWritten := 0
 
 	for _, review := range reviews {
-		if maxReviewers > 0 && reviewersWritten > maxReviewers {
+		if maxReviewers > 0 && reviewersWritten >= maxReviewers {
 			break
 		}
 

models/issues/pull_test.go

@@ -14,6 +14,7 @@ import (
 	"gitea.dev/models/unittest"
 	user_model "gitea.dev/models/user"
 	"gitea.dev/modules/setting"
+	"gitea.dev/modules/test"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -403,6 +404,10 @@ func testGetApprovers(t *testing.T) {
 	approvers := pr.GetApprovers(t.Context())
 	expected := "Reviewed-by: User Five <user5@example.com>\nReviewed-by: Org Six <org6@example.com>\n"
 	assert.Equal(t, expected, approvers)
+
+	defer test.MockVariableValue(&setting.Repository.PullRequest.DefaultMergeMessageMaxApprovers, 1)()
+	approvers = pr.GetApprovers(t.Context())
+	assert.Equal(t, "Reviewed-by: User Five <user5@example.com>\n", approvers)
 }
 
 func testGetPullRequestByMergedCommit(t *testing.T) {