test: Remove trailing spaces from ends of lines in test/ directory. * test/bug-31371.tst, test/bug-36025/@testclass/testclass.m, test/build-sparse-tests.sh, test/classes/@CPrecedenceTester2/CPrecedenceTester2.m, test/classes/@CPrecedenceTester3/CPrecedenceTester3.m, test/classes/@Cork/click.m, test/classes/@Dork/Dork.m, test/classes/@Dork/display.m, test/classes/@Dork/gack.m, test/classes/@Gork/cork.m, test/classes/@Gork/gark.m, test/classes/@Gork/subsasgn.m, test/classes/@Pork/Pork.m, test/classes/@Pork/gurk.m, test/classes/@Snork/gick.m, test/classes/@Spork/geek.m, test/error.tst, test/func.tst, test/index.tst, test/io.tst, test/line-continue.tst, test/prefer.tst, test/switch.tst, test/system.tst, test/try.tst: Remove trailing spaces from ends of lines in test/ directory.

--- a/test/line-continue.tst
+++ b/test/line-continue.tst
@@ -30,7 +30,7 @@
 %! x = [1;2];
 %! y = [a... # comments here ok
 %! ;\
-%! 
+%!
 %! b];
 %! assert (y, x);
 
@@ -58,9 +58,9 @@
 
 %!test
 %! x = [1, ...
-%! 
+%!
 %! ...
-%! 
+%!
 %! 2];
 %! y = [1;2];
 %! assert (y, x);