test: add test for non-intersecting hashmap type constructors

In this test, Valinor considers two disjoint input types as colliding.

Similar to CuyZ#487, this scenario was
detected while trying to map multiple constructors for XML structures
that may present different data depending on singular/plural entries
found:

```xml
<Invoices>
  <Invoice>
    <!-- `Item` is singular, and needs to be handled as `Item` -->
    <Item><Price>123</Price></Item>
  </Invoice>
  <Invoice>
    <!-- `Item` is plural, and needs to be handled as `list<Item>` -->
    <Item><Price>456</Price></Item>
    <Item><Price>789</Price></Item>
  </Invoice>
</Invoices>
```

In CuyZ#487, we attempted to map a single constructor using
`array{foo: T|list<T>}`, while in this patch, we found the issue because
we attempted to attack the problem by declaring separate constructors
that would work on `array{foo: T}` and `array{foo: list<T>}` disjointly,
but failed to do so due to aggressive collision detection logic.

Initially discovered by @Tigerman55

tests/Integration/Mapping/ConstructorRegistrationMappingTest.php

@@ -633,6 +633,33 @@ public function test_identical_registered_constructors_with_several_argument_thr
             ->map(stdClass::class, []);
     }
 
+    public function test_non_intersecting_hashmap_type_constructors_do_not_lead_to_collisions(): void
+    {
+        $mapper = $this->mapperBuilder()
+            ->registerConstructor(
+                /** @param array{key: SimpleObject} $input */
+                static fn (array $input): stdClass => (object)['single-item' => $input],
+                /** @param array{key: list<SimpleObject>} $input */
+                static fn (array $input): stdClass => (object)['multiple-items' => $input],
+            )
+            ->mapper();
+
+        $hello = new SimpleObject();
+        $world = new SimpleObject();
+
+        $hello->value = 'hello';
+        $world->value = 'world';
+
+        try {
+            self::assertEquals(
+                (object) ['multiple-items' => ['key' => [$hello, $world]]],
+                $mapper->map(stdClass::class, ['key' => ['hello', 'world']])
+            );
+        } catch (MappingError $error) {
+            $this->mappingFail($error);
+        }
+    }
+
     public function test_source_not_matching_registered_constructors_throws_exception(): void
     {
         try {