Fix typo in the API Deploy Keys documentation page

changelogs/unreleased/fix_typo_in_deploy_keys_docs.yml

+---
+title: Fix typo in the API Deploy Keys documentation page
+merge_request: 14014
+author: Vitaliy @blackst0ne Klachkov
+type: fixed

doc/api/deploy_keys.md

@@ -106,7 +106,7 @@ Example response:
 Creates a new deploy key for a project.
 
 If the deploy key already exists in another project, it will be joined to current
-project only if original one was is accessible by the same user.
+project only if original one is accessible by the same user.
 
 ```
 POST /projects/:id/deploy_keys