Update pyarrow requirement in /requirements/base

Updates the requirements on [pyarrow](https://github.com/apache/arrow) to permit the latest version.
- [Release notes](https://github.com/apache/arrow/releases)
- [Commits](apache/arrow@go/v16.0.0...apache-arrow-20.0.0)

---
updated-dependencies:
- dependency-name: pyarrow
  dependency-version: 20.0.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements/base/base.txt

@@ -2,7 +2,7 @@ multimethod >= 1.0, < 3.0
 neo4j >= 4.4.12, < 6.0
 numpy < 2.3
 pandas >= 1.0, < 3.0
-pyarrow >= 16.0, < 20.0
+pyarrow >= 16.0, < 21.0
 textdistance >= 4.0, < 5.0
 tqdm >= 4.0, < 5.0
 typing-extensions >= 4.0, < 5.0