Bump pyarrow from 18.0.0 to 18.1.0

Bumps [pyarrow](https://github.com/apache/arrow) from 18.0.0 to 18.1.0.
- [Release notes](https://github.com/apache/arrow/releases)
- [Commits](apache/arrow@apache-arrow-18.0.0...apache-arrow-18.1.0)

---
updated-dependencies:
- dependency-name: pyarrow
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -14,4 +14,4 @@ netcdf4==1.7.2
 h5netcdf==1.4.1
 impactlab-tools==0.6.0
 p_tqdm==1.4.2
-pyarrow==18.0.0
+pyarrow==18.1.0