Configure index in @ParameterizedTest display names

This commit prepends "[{index}] " to all custom display names
configured via @ParameterizedTest.

This provides better diagnostics between the "technical names" reported
on the CI server vs. the "display names" reported within a developer's
IDE.

See gh-23451

spring-context/src/test/java/org/springframework/scheduling/support/CronTriggerTests.java

@@ -857,7 +857,7 @@ class CronTriggerTests {
 
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target(ElementType.METHOD)
-	@ParameterizedTest(name = "localDateTime [{0}], time zone [{1}]")
+	@ParameterizedTest(name = "[{index}] localDateTime[{0}], time zone[{1}]")
 	@MethodSource("parameters")
 	@interface ParameterizedCronTriggerTest {
 	}