How do you resolve conflicts with a protected branch?

[Tyler Lytle]

I have two release branches that have been running parallel for quite some time. The time has come now for release/1.0.0 to be merged into release/2.0.0. The release/1.0.0 branch will go away. 

When I open a pull request, I get a merge conflict. I would like to resolve the merge conflict but the project policy protects release branches from modification without pull requests. 

Is there a way to setup a policy that allows merge commits to be an exception to this rule? I know I can create a conflict resolution branch and then merge that branch into release/2.0.0 but then there is a superfluous branch that then needs to be merged into the release/2.0.0 branch.