fix: add missing property to new action step

Author: foosel

action.yml

@@ -32,6 +32,7 @@ runs:
         [ -z "${{ inputs.config }}"] || [ -f "${{ inputs.config }}" ] || $(echo "Validation error: inputs.config does not exist!" && exit -1)
         [ -z "${{ inputs.environment }}" ] || $(echo '${{ inputs.environment }}' | jq) || $(echo "Validation error: inputs.environment does not contain valid json!" && exit -1)
         [ -z "${{ inputs.custopizer }}" ] || [[ "${{ inputs.custopizer }}" ~= ^[a-zA-Z0-9_][a-zA-Z0-9_.-]{0,127}$ || "${{ inputs.custopizer }}" =~ sha256:[a-f0-9]{64}$ ]] || $(echo "Validation error: inputs.custopizer does not contain a valid version!" && exit -1)
+      shell: bash
 
     - name: "Run CustoPiZer"
       run: |