Drop crun_bin_dir unused var (#9845)

crun_bin_dir was used to specify the destination of the crun binary during the
download process. This path must match with the value provided in the CRI-O
configuration file. So changing its value to bin_dir helps to mismatch errors.

Signed-off-by: Victor Morales <chipahuac@hotmail.com>

roles/container-engine/crun/defaults/main.yml

----
-
-crun_bin_dir: /usr/bin/

roles/container-engine/crun/tasks/main.yml

@@ -7,6 +7,6 @@
 - name: Copy crun binary from download dir
   copy:
     src: "{{ local_release_dir }}/crun"
-    dest: "{{ crun_bin_dir }}/crun"
+    dest: "{{ bin_dir }}/crun"
     mode: 0755
     remote_src: true