cff GitHub action cannot push to main branch

[peterdesmet]

See: https://github.com/inbo/camtrapdp/actions/runs/9805985403/job/27076795427

Action ended on success, but cannot push to main branch and CITATION.cff is not updated.

[main e07bd44] Update CITATION.cff
 1 file changed, 7 insertions(+), 6 deletions(-)
remote: error: GH006: Protected branch update failed for refs/heads/main.        
No changes to commit
remote: error: Changes must be made through a pull request.        
To https://github.com/inbo/camtrapdp
 ! [remote rejected] main -> main (protected branch hook declined)
error: failed to push some refs to 'https://github.com/inbo/camtrapdp'

I think this action should run on PRs (only).