Replace dash with the built-in cl-lib

sample/prelude-pinned-packages.el

@@ -25,7 +25,6 @@
         (cython-mode . "melpa-stable")
         (d-mode . "melpa-stable")
         (dart-mode . "melpa-stable")
-        (dash . "melpa-stable")
         (diff-hl . "melpa-stable")
         (diminish . "melpa-stable")
         (discover-my-major . "melpa-stable")
@@ -92,7 +91,6 @@
         (mediawiki . "melpa-stable")
         (merlin . "melpa-stable")
         (operate-on-number . "melpa-stable")
-        (ov . "melpa-stable")
         (pcache . "melpa-stable")
         (php-mode . "melpa-stable")
         (pkg-info . "melpa-stable")