HSEARCH-4061 Clarify the purpose of Maven property 'version.legacy.junit'

Signed-off-by: Yoann Rodière <yoann@hibernate.org>

Author: yrodiere

integrationtest/showcase/library/pom.xml

@@ -44,10 +44,16 @@
  </exclusion>
  </exclusions>
  </dependency>
+ <!--
+ junit-vintage-engine 5.5.2 version does not support junit 4.13.1.
+ If we try to use it, a parsing error is thrown.
+ So we downgrade JUnit, so that junit-vintage-engine will handle it.
+ See https://stackoverflow.com/a/64371503/1812965
+ -->
  <dependency>
  <groupId>junit</groupId>
  <artifactId>junit</artifactId>
- <version>${version.legacy.junit}</version>
+ <version>${version.junit.junit-platform-workaround}</version>
  <scope>test</scope>
  </dependency>
  </dependencies>

pom.xml

@@ -252,8 +252,9 @@
  junit-vintage-engine 5.5.2 version does not support junit 4.13.1.
  If we try to use it, a parsing error is thrown.
  So we downgrade JUnit, so that junit-vintage-engine will handle it.
+ See https://stackoverflow.com/a/64371503/1812965
  -->
- <version.legacy.junit>4.13</version.legacy.junit>
+ <version.junit.junit-platform-workaround>4.13</version.junit.junit-platform-workaround>
 
  <version.org.hamcrest>2.2</version.org.hamcrest>
  <version.org.mockito>3.5.13</version.org.mockito>