fix(action): use the correct id for lock

[kdihalas]

This pull request fixes an issue with the pull request locking action by ensuring that the correct step ID is used when referencing lock acquisition outputs. This change ensures that the outputs correctly reflect the results of the intended step.

Action output references update:

• Updated the output references in action.yml to use the correct step ID (lock instead of acquire-lock) for both lock_acquired and lock_owner outputs.

Documentation:

• Added a changeset entry describing the patch and the correction to the lock ID usage.