Fix crash when action notification cell label leaks

Tusker/Screens/Notifications/ActionNotificationGroupCollectionViewCell.swift

@@ -60,7 +60,7 @@ class ActionNotificationGroupCollectionViewCell: UICollectionViewListCell {
         $0.adjustsFontForContentSizeCategory = true
         $0.numberOfLines = 2
         $0.lineBreakMode = .byTruncatingTail
-        $0.combiner = { [unowned self] in self.updateActionLabel(names: $0) }
+        $0.combiner = { [weak self] in self?.updateActionLabel(names: $0) ?? NSAttributedString() }
     }
     
     private let statusContentLabel = UILabel().configure {

Tusker/Views/MultiSourceEmojiLabel.swift

@@ -24,21 +24,18 @@ class MultiSourceEmojiLabel: UILabel, BaseEmojiLabel {
         
         var attributedStrings = pairs.map { NSAttributedString(string: $0.0) }
         
-        func recombine() {
-            if let combiner = self.combiner {
+        let recombine = { [weak self] in
+            if let self,
+               let combiner = self.combiner {
                 self.attributedText = combiner(attributedStrings)
             }
         }
-        
         recombine()
         
         for (index, (string, emojis)) in pairs.enumerated() {
             self.replaceEmojis(in: string, emojis: emojis, identifier: identifier) { (attributedString, _) in
                 attributedStrings[index] = attributedString
-                DispatchQueue.main.async { [weak self] in
-                    guard let self else { return }
-                    recombine()
-                }
+                DispatchQueue.main.async(execute: recombine)
             }
         }
     }