chore(deps): update dependency pyarrow to v20 (#13323)

* chore(deps): update dependency pyarrow to v20

* Pin Python 3.8 versions

* formatting

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Co-authored-by: Katie McLaughlin <[email protected]>

Author: renovate-bot

bigquery/bqml/requirements.txt

@@ -3,6 +3,6 @@ google-cloud-bigquery-storage==2.27.0
 pandas==2.0.3; python_version == '3.8'
 pandas==2.2.3; python_version > '3.8'
 pyarrow==17.0.0; python_version <= '3.8'
-pyarrow==19.0.0; python_version > '3.9'
+pyarrow==20.0.0; python_version > '3.9'
 flaky==3.8.1
 mock==5.1.0

bigquery/pandas-gbq-migration/requirements.txt

@@ -5,4 +5,4 @@ pandas==2.2.3; python_version > '3.8'
 pandas-gbq==0.24.0
 grpcio==1.69.0
 pyarrow==17.0.0; python_version <= '3.8'
-pyarrow==19.0.0; python_version > '3.9'
+pyarrow==20.0.0; python_version > '3.9'