Remove the single remaining test that tested a double click beyond
the end of the line in a Java 15 text block. This depends on the SWT
version the test is run with: older SWT versions would not select
anything, newer ones will select the last "word" on the line.

Change-Id: Id38fdbf3af7c97c13adeec19c6cb583ca8a2807a
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Reviewed-on: https://git.eclipse.org/r/c/jdt/eclipse.jdt.ui/+/185689
Tested-by: JDT Bot <jdt-bot@eclipse.org>
Reviewed-by: Andrey Loskutov <loskutov@gmx.de>