Fix Windows path issue in JarFileWrapperTests

See gh-22991

spring-boot-project/spring-boot-tools/spring-boot-loader/src/test/java/org/springframework/boot/loader/jar/JarFileWrapperTests.java

@@ -137,7 +137,7 @@ class JarFileWrapperTests {
 
 	@Test
 	void toStringDelegatesToParent() {
-		assertThat(this.wrapper.toString()).endsWith("/temp.jar");
+		assertThat(this.wrapper.toString()).endsWith("temp.jar");
 	}
 
 	@Test // gh-22991