GitHub.DistributedTask.ObjectTemplating.TemplateValidationException: The template is not valid. /home/runner/work/etcher/etcher/./.github/actions/test/action.yml (Line: 31, Col: 7): Required property is missing: shell,/home/runner/work/etcher/etcher/./.github/actions/test/action.yml (Line: 48, Col: 7): Required property is missing: shell,/home/runner/work/etcher/etcher/./.github/actions/test/action.yml (Line: 58, Col: 7): Required property is missing: shell,/home/runner/work/etcher/etcher/./.github/actions/test/action.yml (Line: 62, Col: 7): 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)