Update requiresUnpack documentation of unpack location

The unpack location is (largely) an implementation detail and the
Repackage Mojo was the only place where it was explicity documented.
Rather than updating the outdated location, this commit removes it
entirely to avoid encouraging people to rely on the location.

Closes gh-6624

Author: wilkinsona

spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/RepackageMojo.java

@@ -95,11 +95,10 @@ public class RepackageMojo extends AbstractDependencyFilterMojo {
 
 	/**
 	 * Classifier to add to the artifact generated. If given, the artifact will be
-	 * attached with that classifier and the main artifact will be deployed as the
-	 * main artifact. If this is not given (default), it will replace the
-	 * main artifact and only the repackaged artifact will be deployed. Attaching
-	 * the artifact allows to deploy it alongside to
-	 * the original one, see <a href=
+	 * attached with that classifier and the main artifact will be deployed as the main
+	 * artifact. If this is not given (default), it will replace the main artifact and
+	 * only the repackaged artifact will be deployed. Attaching the artifact allows to
+	 * deploy it alongside to the original one, see <a href=
 	 * "http://maven.apache.org/plugins/maven-deploy-plugin/examples/deploying-with-classifiers.html"
 	 * > the maven documentation for more details</a>.
 	 * @since 1.0
@@ -128,7 +127,7 @@ public class RepackageMojo extends AbstractDependencyFilterMojo {
 	 * A list of the libraries that must be unpacked from fat jars in order to run.
 	 * Specify each library as a <code>&lt;dependency&gt;</code> with a
 	 * <code>&lt;groupId&gt;</code> and a <code>&lt;artifactId&gt;</code> and they will be
-	 * unpacked at runtime in <code>$TMPDIR/spring-boot-libs</code>.
+	 * unpacked at runtime.
 	 * @since 1.1
 	 */
 	@Parameter