Don't panic if next release is not set

Should be usually not the case, but we skip releases from
schedule-builder if the `next` field is not available now.

Signed-off-by: Sascha Grunert <[email protected]>

cmd/schedule-builder/cmd/markdown.go

@@ -173,6 +173,11 @@ func updatePatchSchedule(refTime time.Time, schedule PatchSchedule, eolBranches
 	removeSchedules := []int{}
 	for i, sched := range schedule.Schedules {
 		for {
+			if sched.Next == nil {
+				logrus.Warnf("Next release not set for %s, skipping", sched.Release)
+				break
+			}
+
 			eolDate, err := time.Parse(refDate, sched.EndOfLifeDate)
 			if err != nil {
 				return fmt.Errorf("parse end of life date: %w", err)

cmd/schedule-builder/cmd/markdown_test.go

@@ -366,6 +366,9 @@ func TestUpdatePatchSchedule(t *testing.T) {
 						EndOfLifeDate:            "2025-01-01",
 						MaintenanceModeStartDate: "2024-12-01",
 					},
+					{ // next not set
+						Release: "1.29",
+					},
 					{ // EOL
 						Release:       "1.20",
 						EndOfLifeDate: "2023-01-01",
@@ -423,6 +426,9 @@ func TestUpdatePatchSchedule(t *testing.T) {
 							},
 						},
 					},
+					{
+						Release: "1.29",
+					},
 				},
 				UpcomingReleases: []*PatchRelease{
 					{