[Fixed JENKINS-53608] Incorect method signatures of readResolve()

core/src/main/java/hudson/triggers/SCMTrigger.java

@@ -245,10 +245,11 @@ public class SCMTrigger extends Trigger<Item> {
         private static final int THREADS_UPPER_BOUND = 100;
         private static final int THREADS_DEFAULT= 10;
 
-        private void readResolve() {
+        private Object readResolve() {
             if (maximumThreads == 0) {
                 maximumThreads = THREADS_DEFAULT;
             }
+            return this;
         }
 
         public boolean isApplicable(Item item) {

core/src/main/java/jenkins/security/apitoken/ApiTokenStats.java

@@ -60,7 +60,7 @@ public class ApiTokenStats implements Saveable {
         this.init();
     }
     
-    private ApiTokenStats readResolve() {
+    private Object readResolve() {
         this.init();
         return this;
     }
@@ -217,7 +217,7 @@ public class ApiTokenStats implements Saveable {
             this.tokenUuid = tokenUuid;
         }
         
-        private SingleTokenStats readResolve() {
+        private Object readResolve() {
             if (this.useCounter != null) {
                 // to avoid negative numbers to be injected
                 this.useCounter = Math.max(0, this.useCounter);