removed an unnecessary function

decodertest.py

@@ -29,13 +29,6 @@
 import train.decoder_train as dt
 from visualize.plot import spectra_plot
 
-def build_dict(df, key):
-    df = df.select(key, f"{key}_str").distinct()
-
-    return df.rdd.map(
-        lambda row: (str(np.argmax(row[key])), row[f"{key}_str"])
-    ).collectAsMap()
-
 def multi_gpu():
     devices = jax.devices("gpu")
     mesh = keras.distribution.DeviceMesh(