fix scalar indexing in Oceananigans.OutputReaders.FieldTimeSeries

Author: navidcy

experiments/ClimaEarth/Project.toml

@@ -48,6 +48,6 @@ CUDA = "5"
 EnsembleKalmanProcesses = "2"
 Interpolations = "0.14, 0.15"
 JLD2 = "0.5"
-Oceananigans = "0.96"
+Oceananigans = "0.97.1"
 StaticArrays = "1"
 YAML = "0.4"