Zuul encountered a syntax error while parsing its configuration in the
repo osism/kolla-operations on branch main. The error was:

'str' object does not support item assignment

The error appears in the following project stanza:

project:
default-branch: main
merge-mode: squash-merge
check:
jobs:
- yamllint
- name: ansible-lint
files: ^.src/playbooks/..(yaml|yml)$
- name: check-shell-syntax
files: ^.src/files/mixins.sh$
- name: mixin-ouput-ensure-git-checkin
files: ^.src/.$

in "osism/kolla-operations/.zuul.yaml@main", line 6, column 3