[codespell] fix typos

This change fixes typos in tempest code, doc, zuul yaml
and tox.ini file, which are found by codespell.

Change-Id: I8051d979e28f7dbf532181f339cbef9cd7220c76
diff --git a/zuul.d/stable-jobs.yaml b/zuul.d/stable-jobs.yaml
index a662685..429c014 100644
--- a/zuul.d/stable-jobs.yaml
+++ b/zuul.d/stable-jobs.yaml
@@ -103,7 +103,7 @@
       devstack_plugins:
         neutron: https://opendev.org/openstack/neutron
       devstack_services:
-        # Enbale horizon so that we can run horizon test.
+        # Enable horizon so that we can run horizon test.
         horizon: true
 
 - job: