Add protectedBranches to ApprovalRule

This is returned by GitLab and simply not mapped yet. Tested with Gitlab 18.0.2

Author: christophbrill-cgmcom

gitlab4j-models/src/main/java/org/gitlab4j/api/models/ApprovalRule.java

@@ -19,6 +19,7 @@ public class ApprovalRule implements Serializable {
     private Boolean containsHiddenGroups;
     private List<User> approvedBy;
     private Boolean approved;
+    private List<ProtectedBranch> protectedBranches;
 
     public Long getId() {
         return id;
@@ -108,6 +109,14 @@ public void setApproved(Boolean approved) {
         this.approved = approved;
     }
 
+    public List<ProtectedBranch> getProtectedBranches() {
+        return protectedBranches;
+    }
+
+    public void setProtectedBranches(List<ProtectedBranch> protectedBranches) {
+        this.protectedBranches = protectedBranches;
+    }
+
     @Override
     public String toString() {
         return (JacksonJson.toJsonString(this));