Make minor fixes to the crate claim workflow (#2259)

# This workflow claims the names of the unpublished crates in this repository

# on crates.io (by publishing a dummy empty package)

# Allow only one release to run at a time

# Allow only one crate claim workflow to run at a time

concurrency:

  group: release-smithy-rs

  group: claim-crates-smithy-rs

  cancel-in-progress: true

env:

  claim:

    name: Claim crate names

    needs:

    - main-branch-check

    - acquire-base-image

    runs-on: ubuntu-latest

    steps:

        toolchain: ${{ env.rust_version }}

    - name: Checkout smithy-rs

      uses: actions/checkout@v3

      with:

        token: ${{ secrets.RELEASE_AUTOMATION_BOT_PAT }}

    - name: Publish to crates.io

      shell: bash

      env: