Do not require explicit override for plugin-generated methods

mypy/checker.py

@@ -1924,11 +1924,14 @@ def check_explicit_override_decorator(
         found_method_base_classes: list[TypeInfo] | None,
         context: Context | None = None,
     ) -> None:
+        sym = defn.info.get(defn.name)
         if (
             found_method_base_classes
             and not defn.is_explicit_override
             and defn.name not in ("__init__", "__new__")
             and not is_private(defn.name)
+            and sym is not None
+            and not sym.plugin_generated
         ):
             self.msg.explicit_override_decorator_missing(
                 defn.name, found_method_base_classes[0].fullname, context or defn

test-data/unit/check-dataclasses.test

@@ -2465,7 +2465,7 @@ class Foo:
 
 [case testDataclassInheritanceWorksWithExplicitOverrides]
 # flags: --enable-error-code explicit-override
-from dataclasses  import dataclass
+from dataclasses import dataclass
 
 @dataclass
 class Base:
@@ -2475,3 +2475,16 @@ class Base:
 class Child(Base):
     y: int
 [builtins fixtures/dataclasses.pyi]
+
+[case testDataclassInheritanceWorksWithExplicitOverridesAndOrdering]
+# flags: --enable-error-code explicit-override
+from dataclasses import dataclass
+
+@dataclass(order=True)
+class Base:
+    x: int
+
+@dataclass(order=True)
+class Child(Base):
+    y: int
+[builtins fixtures/dataclasses.pyi]