adomani/get_mathlib4_with_cache/v1/action.yaml (Line: 7, Col: 11): Unexpected symbol: 'MAIN_OR_FORK'. Located at position 19 within expression: github.repository MAIN_OR_FORK 'leanprover-community/mathlib4'

GitHub.DistributedTask.ObjectTemplating.TemplateValidationException: The template is not valid. adomani/get_mathlib4_with_cache/v1/action.yaml (Line: 7, Col: 11): Unexpected symbol: 'MAIN_OR_FORK'. Located at position 19 within expression: github.repository MAIN_OR_FORK 'leanprover-community/mathlib4' 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)