/home/runner/work/bundler/bundler/./action.yml (Line: 39, Col: 11): Required property is missing: shell

/home/runner/work/bundler/bundler/./action.yml: (Line: 65, Col: 9, Idx: 1963) - (Line: 65, Col: 9, Idx: 1963): While parsing a block collection, did not find expected '-' indicator.

System.ArgumentException: Unexpected type '' encountered while reading 'action manifest root'. The type 'MappingToken' was expected. at GitHub.DistributedTask.ObjectTemplating.Tokens.TemplateTokenExtensions.AssertMapping(TemplateToken value, String objectDescription) at GitHub.Runner.Worker.ActionManifestManager.Load(IExecutionContext executionContext, String manifestFile)