/Users/runner/work/flare/flare/./.github/actions/publish_pages/action.yml (Line: 13, Col: 7): Required property is missing: shell

GitHub.DistributedTask.ObjectTemplating.TemplateValidationException: The template is not valid. /Users/runner/work/flare/flare/./.github/actions/publish_pages/action.yml (Line: 13, 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)

Failed to load /Users/runner/work/flare/flare/./.github/actions/publish_pages/action.yml

Node.js 16 actions are deprecated. Please update the following actions to use Node.js 20: actions/checkout@v3. For more information see: https://github.blog/changelog/2023-09-22-github-actions-transitioning-from-node-16-to-node-20/.