Don't use strings.Cut

Looks like that function was added in go 1.18 but this project is using go 1.16

https://pkg.go.dev/[email protected]#Cut

pkg/api/config.go

@@ -42,7 +42,14 @@ func (cfg Config) GetGlobalDestinations(labels map[string]string) services.Desti
 		for _, trigger := range triggers {
 			if s.MatchesTrigger(trigger) && s.Selector.Matches(fields.Set(labels)) {
 				for _, recipient := range s.Recipients {
-					before, after, _ := strings.Cut(recipient, ":")
+					var before, after string
+					if i := strings.Index(recipient, ":"); i > 0 {
+						before = recipient[:i]
+						after = recipient[i+1:]
+					} else {
+						before = recipient
+						after = ""
+					}
 					dest := services.Destination{Service: before}
 					if len(after) > 0 {
 						dest.Recipient = after

pkg/cmd/template.go

@@ -62,7 +62,14 @@ func newTemplateNotifyCommand(cmdContext *commandContext) *cobra.Command {
 			}
 
 			for _, recipient := range recipients {
-				before, after, _ := strings.Cut(recipient, ":")
+				var before, after string
+				if i := strings.Index(recipient, ":"); i > 0 {
+					before = recipient[:i]
+					after = recipient[i+1:]
+				} else {
+					before = recipient
+					after = ""
+				}
 				dest := services.Destination{Service: before}
 				if len(after) > 0 {
 					dest.Recipient = after

pkg/services/matrix.go

@@ -63,7 +63,12 @@ func (s *matrixService) Send(notification Notification, dest Destination) error
 			return fmt.Errorf("couldn't resolve room alias '%s': %w", dest.Recipient, err)
 		}
 		roomID = resp.RoomID
-		_, serverName, _ = strings.Cut(roomAlias.String(), ":")
+		roomAliasStr := roomAlias.String()
+		if i := strings.Index(roomAliasStr, ":"); i > 0 {
+			serverName = roomAliasStr[i+1:]
+		} else {
+			serverName = ""
+		}
 	}
 
 	markdownContent := format.RenderMarkdown(notification.Message, true, true)