Add check for the organization name for the "lock-issues" job

[MurzNN]

When I fork the Payload repo into my own namespace, I start to receive errors every day like this:

[Murz-forks/payload-issues] Run failed: lock-issues - main (eecf87b)

And, I suppose, other forkers have the same issue.

To fix this, I think, we can add a check that the organization name is "payloadcms" and skip the job if not.