Tests: Refactor filter assertion in get_post() tests

Moves the filter property assertion into the appropriate conditional blocks and removes the redundant final if statement for better code structure.

Co-authored-by: gemini-cli <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: westonruter

tests/phpunit/tests/post/getPost.php

@@ -76,9 +76,12 @@ public function test_get_post( callable $input, string $output, string $filter,
 			$this->assertIsArray( $post );
 			$this->assertArrayHasKey( 'ID', $post );
 			$this->assertSame( $expected_id_val, $post['ID'] );
+			$this->assertArrayHasKey( 'filter', $post );
+			$this->assertSame( $filter, $post['filter'] );
 		} elseif ( ARRAY_N === $output ) {
 			$this->assertIsArray( $post );
 			$this->assertContains( $expected_id_val, $post );
+			$this->assertContains( $filter, $post );
 		} else {
 			$this->assertInstanceOf( WP_Post::class, $post );
 
@@ -87,9 +90,6 @@ public function test_get_post( callable $input, string $output, string $filter,
 			}
 
 			$this->assertSame( $expected_id_val, $post->ID );
-		}
-
-		if ( $post instanceof WP_Post ) {
 			$this->assertSame( $filter, $post->filter );
 		}
 	}