Allow --dry-run option to ignore configured release branches

[walshta]

New feature motivation

For testing if a PR will not cause a release failure, I've configured my GH Actions to run semantic release on any PR targeting a release branch. Since this run is using the --dry-run option it should be safe to run on a PR. This allows for a status check to be required and block any PR that would cause a release failure.

New feature description

Prior to checking if the current branch is a configured release branch or a pull request, check if the --dry-run option was specified. If it was and this is a dry run, allow the process to continue and publish a message stating that this is a dry run and no new version will be published. The expected behavior of a dry run is to run to completion without creating a new version.

New feature implementation

No response