GitHub.DistributedTask.ObjectTemplating.TemplateValidationException: The template is not valid. /home/runner/work/pulumi-cdk/pulumi-cdk/./.github/actions/build/action.yml (Line: 16, Col: 9): Required property is missing: shell,/home/runner/work/pulumi-cdk/pulumi-cdk/./.github/actions/build/action.yml (Line: 18, Col: 9): Required property is missing: shell,/home/runner/work/pulumi-cdk/pulumi-cdk/./.github/actions/build/action.yml (Line: 20, Col: 9): Required property is missing: shell,/home/runner/work/pulumi-cdk/pulumi-cdk/./.github/actions/build/action.yml (Line: 22, Col: 9): Required property is missing: shell
at GitHub.DistributedTask.ObjectTemplating.TemplateValidationErrors.Check()
at GitHub.Runner.Worker.ActionManifestManager.ConvertRuns(IExecutionContext executionContext, TemplateContext templateContext, TemplateToken inputsToken, String fileRelativePath, MappingToken outputs)
at GitHub.Runner.Worker.ActionManifestManager.Load(IExecutionContext executionContext, String manifestFile)