Remove assertions that would break for WP < 6.5

phpunit/blocks/block-json-variations-filename-test.php

@@ -42,13 +42,7 @@ public function test_register_block_type_from_metadata_with_variations_php_file(
 
 		$this->assertInstanceOf( 'WP_Block_Type', $result, 'The block was not registered' );
 
-		$this->assertIsCallable( $result->variation_callback, 'The variation callback hasn\'t been set' );
 		$expected_variations = require GUTENBERG_DIR_TESTFIXTURES . '/variations.php';
-		$this->assertSame(
-			$expected_variations,
-			call_user_func( $result->variation_callback ),
-			'The variation callback hasn\'t been set correctly'
-		);
-		$this->assertSame( $expected_variations, $result->variations, 'The block variations are incorrect' );
+		$this->assertSame( $expected_variations, $result->variations, "Block variations haven't been set correctly." );
 	}
 }