Cleanup of code related to old non supported Java version

[olamy]

Affected version

3.11-

Bug description

Such code is not usefull anymore as we are java 8 minimum required

maven-javadoc-plugin/src/main/java/org/apache/maven/plugins/javadoc/AbstractJavadocMojo.java

Line 222 in 28ab2ac

private static final JavaVersion SINCE_JAVADOC_1_4 = JavaVersion.parse("1.4");

[olamy]

done