add conditional execution of action steps

Describe the enhancement Add possibility to use if: option for action steps of composite actions.

Code Snippet

inputs:
  echo-bla:
    description: 'echo bla-bla-bla if not empty'
    required: true
runs:
  using: "composite"
  steps:
    - run: echo "start"
      shell: bash
    - run: echo "bla bla bla"
      shell: bash
      if: ${{ inputs.echo-bla }}
    - run: echo "stop"
      shell: bash

[fhammerl]

Release announcement: https://github.blog/changelog/2021-11-09-github-actions-conditional-execution-of-steps-in-actions/

[fearphage]

Please do not add +1’s to this issue. Just use the reactions on the first post instead. You’re pinging everyone that’s subscribed to this issue and providing no value.