Re-enable support for invalid Expires attributes in MockCookie

Changes introduced in commit 9b2087618b
caused a regression for Cookie support in MockHttpServletResponse.
Specifically, an Expires attribute that cannot be parsed using
`ZonedDateTime.parse()` now results in an exception; whereas,
previously an entry such as `Expires=0` was allowed.

This commit fixes this issue in MockCookie by catching and ignoring any
DateTimeException thrown while attempting to parse an Expires attribute.

Closes gh-23911

spring-test/src/main/java/org/springframework/mock/web/MockCookie.java

@@ -16,6 +16,7 @@
 
 package org.springframework.mock.web;
 
+import java.time.DateTimeException;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 
@@ -31,6 +32,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Vedran Pavic
  * @author Juergen Hoeller
+ * @author Sam Brannen
  * @since 5.1
  */
 public class MockCookie extends Cookie {
@@ -119,8 +121,13 @@ public class MockCookie extends Cookie {
 				cookie.setMaxAge(Integer.parseInt(extractAttributeValue(attribute, setCookieHeader)));
 			}
 			else if (StringUtils.startsWithIgnoreCase(attribute, "Expires")) {
-				cookie.setExpires(ZonedDateTime.parse(extractAttributeValue(attribute, setCookieHeader),
-						DateTimeFormatter.RFC_1123_DATE_TIME));
+				try {
+					cookie.setExpires(ZonedDateTime.parse(extractAttributeValue(attribute, setCookieHeader),
+							DateTimeFormatter.RFC_1123_DATE_TIME));
+				}
+				catch (DateTimeException ex) {
+					// ignore invalid date formats
+				}
 			}
 			else if (StringUtils.startsWithIgnoreCase(attribute, "Path")) {
 				cookie.setPath(extractAttributeValue(attribute, setCookieHeader));