Update actions used in respec workflow

[lornajane]

Update the github workflow that runs respec. By updating the actions, hopefully eliminate the error and warnings that we're currently seeing from this action. Fixes #3629

[handrews]

Does this mean we should update the peter-evans/create-pull-request package in pacakge.json and the package lock file?

• Figure out if we need to update peter-evans/create-pull-request from 5 to 6 #3553

I'd declined the dependabot PR (#3539) for that package because of the major version change but we could incorporate it here? Or do these actions install based on their own set of dependencies, and not the ones in our repo?

[lornajane]

I think the actions are independent. But that makes me wonder what the package is doing in our dependencies.