Increase the test framework timeout from 5s to 60s

It seems that some of the test environments hit the 5s timeout on
some tests.  Since it doesn't really matter, as long as we don't
hang forever, increase the timeout to 60s.

* tests/test_driver.pl: Increase $test_timout to 60.  We don't need
to handle VMS timeouts specially anymore.
* tests/scripts/features/parallelism: We don't need to override the
default timeout anymore.
* tests/scripts/features/patternrules: Remove confusing comment.

tests/scripts/features/patternrules

@@ -196,7 +196,7 @@ all: foo.x foo-mt.x
               '', "one\ntwo");
 
 # Test pattern rules building the same targets
-# See SV 54233.  Rely on our standard test timeout to break the loop
+# See SV 54233.
 
 touch('a.c');