Add phpstan assertions for last in Collection isEmpty and isNotEmpty (#53107)

Author: bastien-phi

src/Illuminate/Collections/Collection.php

@@ -690,8 +690,10 @@ public function intersectByKeys($items)
      * Determine if the collection is empty or not.
      *
      * @phpstan-assert-if-true null $this->first()
+     * @phpstan-assert-if-true null $this->last()
      *
      * @phpstan-assert-if-false TValue $this->first()
+     * @phpstan-assert-if-false TValue $this->last()
      *
      * @return bool
      */

src/Illuminate/Collections/Traits/EnumeratesValues.php

@@ -366,8 +366,10 @@ public function ensure($type)
      * Determine if the collection is not empty.
      *
      * @phpstan-assert-if-true TValue $this->first()
+     * @phpstan-assert-if-true TValue $this->last()
      *
      * @phpstan-assert-if-false null $this->first()
+     * @phpstan-assert-if-false null $this->last()
      *
      * @return bool
      */