Fix UriPathEncoder bug to improve performance

Fix `isAllowed` check and write test to ensure that additional object
instances are not created unnecessarily.

See gh-40615

spring-boot-project/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/nio/file/UriPathEncoder.java

@@ -36,7 +36,7 @@ final class UriPathEncoder {
 	static String encode(String path) {
 		byte[] bytes = path.getBytes(StandardCharsets.UTF_8);
 		for (byte b : bytes) {
-			if (isAllowed(b)) {
+			if (!isAllowed(b)) {
 				return encode(bytes);
 			}
 		}