fix: fix setReadonly when using binder with records (#20855)

When Binder is used with record, calling setReadonly method does not have
any effect because the logic only considers bindings with a proper setter.
This change fixes the setReadonly logic to take care of all bindings when
Binder is using a record.

Fixes #20854

flow-data/src/main/java/com/vaadin/flow/data/binder/Binder.java

@@ -1659,7 +1659,7 @@ private void convertAndSetFieldValue(TARGET modelValue) {
 
         @Override
         public void setReadOnly(boolean readOnly) {
-            if (setter == null && !readOnly) {
+            if (!binder.isRecord && this.setter == null && !readOnly) {
                 throw new IllegalStateException(
                         "Binding with a null setter has to be read-only");
             }
@@ -3535,7 +3535,8 @@ public boolean hasChanges(Binding<BEAN, ?> binding) {
      *            to set them to read-write
      */
     public void setReadOnly(boolean readOnly) {
-        getBindings().stream().filter(binding -> binding.getSetter() != null)
+        getBindings().stream()
+                .filter(binding -> isRecord || binding.getSetter() != null)
                 .forEach(field -> field.setReadOnly(readOnly));
     }
 

flow-data/src/test/java/com/vaadin/flow/data/binder/BinderTest.java

@@ -1303,6 +1303,23 @@ public void setReadonlyShouldIgnoreBindingsWithNullSetter() {
         assertTrue("Age field should be readonly", ageField.isReadOnly());
     }
 
+    @Test
+    public void setReadonly_record_allFieldsAreReadonly() {
+        Binder<TestRecord> binder = new Binder<>(TestRecord.class);
+        binder.forField(nameField).bind("name");
+        binder.forField(ageField).bind("age");
+
+        binder.getBinding("name").ifPresent(b -> b.setReadOnly(true));
+        binder.setReadOnly(true);
+        assertTrue("Name field should be readonly", nameField.isReadOnly());
+        assertTrue("Age field should be readonly", ageField.isReadOnly());
+
+        binder.setReadOnly(false);
+        assertFalse("Name field should not be readonly",
+                nameField.isReadOnly());
+        assertFalse("Age field should not be readonly", ageField.isReadOnly());
+    }
+
     @Test
     public void isValidTest_bound_binder() {
         binder.forField(nameField)