fix: Use repo owner user for git operations

[xitij2000]

Cherry pick of: openedx-unsupported#6717

Configuration Pull Request

Make sure that the following steps are done before merging

• A devops team member has commented with 👍
• are you adding any new default values that need to be overridden when this goes live?
  • Open a ticket (DEVOPS) to make sure that they have been added to secure vars.
  • Add an entry to the CHANGELOG.
• Are you adding/updating any variables that need to be added/updated to a specific configuration-secure repo?

[Agrendalath]

👍

• I tested this: verified it's a clean cherry-pick, read the vulnerability announcement
• I read through the code
• I checked for accessibility issues: n/a
• Includes documentation: n/a
• I made sure any change in configuration variables is reflected in the corresponding client's configuration-secure repository: n/a