Display a better name for the version bump step in the snap action.

[dibarbet]

The branch snap github action has an unclear name for the second step, 'create-pull-request'

https://github.com/dotnet/vscode-csharp/blob/main/.github/workflows/branch-snap.yml#L15

This should be named something else to indicate that it is only for creating the version bump PRs in main.