Add InvalidOverride issue

docs/running_psalm/issues/InvalidOverride.md

@@ -0,0 +1,24 @@
+# InvalidOverride
+
+Emitted when an `Override` attribute was added to a method that does not override a method from a parent class or implemented interface.
+
+```php
+<?php
+
+class A {
+    function receive()
+    {
+    }
+}
+
+class B extends A {
+    #[Override]
+    function recieve()
+    {
+    }
+}
+```
+
+## Why this is bad
+
+A fatal error will be thrown.

src/Psalm/Issue/InvalidOverride.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Psalm\Issue;
+
+final class InvalidOverride extends CodeIssue
+{
+    public const ERROR_LEVEL = 7;
+    public const SHORTCODE = 357;
+}