TASK-HANDLER-BIND does not accept compound type specifiers

The documentation string of ``task-handler-bind`` claims that it works like ``handler-bind`` but it actually only accepts symbols as condition type specifiers:

```lisp
(lparallel:task-handler-bind (((and error (not undefined-function)) #'continue)) …)
=> Ill-formed binding in `task-handler-bind': ((AND ERROR (NOT UNDEFINED-FUNCTION)) #'CONTINUE)
```