Stub EntityRepository in the autocomplete test for lowest-deps Prophecy

The lowest version of Doctrine ORM exposes at least one inherited
EntityRepository method whose signature contains an intersection type.
Prophecy's class mirror refuses to double such classes
("Doubling intersection types is not supported"), so the unit-tests
matrix was red on every lowest job.

Swap the prophesized EntityRepository for a no-op anonymous-class
subclass — the closure under test never reads the repository argument
anyway, so all we need is an instance of the correct type to satisfy
the signature. Bypassing the parent constructor leaves the readonly
properties uninitialized but, again, nothing in the test path touches
them.

Author: loevgaard

tests/Form/Type/ProductVariantAutocompleteTypeTest.php

@@ -94,7 +94,15 @@ public function the_resolved_filter_query_scopes_the_query_builder_to_the_suppli
             ->willReturn($qbReveal)
         ;
 
-        $repository = $this->prophesize(EntityRepository::class)->reveal();
+        // Prophecy's class mirror chokes on intersection types reached through Doctrine's lowest
+        // EntityRepository ancestors, so we hand-roll a no-op subclass. The closure never reads the
+        // repository argument — it just needs an instance of the right type to satisfy the call.
+        $repository = new class() extends EntityRepository {
+            /** @phpstan-ignore constructor.missingParentCall (intentional — see comment above) */
+            public function __construct()
+            {
+            }
+        };
 
         $filterQuery($qbReveal, 'any-search-query', $repository);
     }