Recast Total threshold criteria exceeded to int (#1848)

In writing tests to verify the output of the tiles csv matches the final
score CSV, I noticed TC/Total threshold criteria exceeded was getting
cast from an int64 to a float64 in the process of PostScoreETL. I
tracked it down to the line where we merge the score dataframe with
constants.DATA_CENSUS_CSV_FILE_PATH --- there where > 100 tracts in the
national census CSV that don't exist in the score, so those ended up
with a Total threshhold count of np.nan, which is a float, and thereby
cast those columns to float. For the moment I just cast it back.

data/data-pipeline/data_pipeline/etl/score/etl_score_post.py

@@ -92,7 +92,9 @@ def _extract_states(self, state_path: Path) -> pd.DataFrame:
     def _extract_score(self, score_path: Path) -> pd.DataFrame:
         logger.info("Reading Score CSV")
         df = pd.read_csv(
-            score_path, dtype={self.GEOID_TRACT_FIELD_NAME: "string"}
+            score_path,
+            dtype={self.GEOID_TRACT_FIELD_NAME: "string"},
+            low_memory=False,
         )
 
         # Convert total population to an int
@@ -237,6 +239,11 @@ def _create_score_data(
             subset=[DISADVANTAGED_COMMUNITIES_FIELD]
         )
 
+        # recast threshold count to integer
+        de_duplicated_df[field_names.THRESHOLD_COUNT] = de_duplicated_df[
+            field_names.THRESHOLD_COUNT
+        ].astype(int)
+
         # set the score to the new df
         return de_duplicated_df