Added extra date time parsing test

Author: rozza

src/test/java/com/mongodb/kafka/connect/util/FlexibleDateTimeParserTest.java

@@ -61,6 +61,7 @@ void testDefaultDateStrings() {
         () ->
             assertEquals(
                 3600001, DEFAULT_DATE_TIME_PARSER.toEpochMilli("1970-01-01T01:00:00.001Z")),
+        () -> assertEquals(3600000, DEFAULT_DATE_TIME_PARSER.toEpochMilli("1970-01-01T01:00:00Z")),
         () ->
             assertEquals(3600001, DEFAULT_DATE_TIME_PARSER.toEpochMilli("1970-01-0101:00:00.001")),
         () -> assertEquals(3600000, DEFAULT_DATE_TIME_PARSER.toEpochMilli("1970-01-0101:00:00")),