* feat: support jsonExtension in LoadJobConfig

* reformatted with black

* Updated doc string and added test for the encoding of jsonExtension

* modified setter test to make sure property is set correctly

fix: init mp pool & grpc client once, use os.sched_setaffinity

- mp pool is initalize once per benchmark run, otherwise time to init
pool is affecting throughput calculations.
- grpc client should be intialized once per process in an event loop,
otherwise processes get stuck .
- os.sched_setaffinity helps in pinning the process to a set of cores to
avoid hard irq from nic.

PR created by the Librarian CLI to initialize a release. Merging this PR
will auto trigger a release.

Librarian Version: v1.0.2-0.20251119154421-36c3e21ad3ac
Language Image:
us-central1-docker.pkg.dev/cloud-sdk-librarian-prod/images-prod/python-librarian-generator@sha256:8e2c32496077054105bd06c54a59d6a6694287bc053588e24debe6da6920ad91
<details><summary>google-cloud-storage: 3.10.0</summary>

##
[3.10.0](googleapis/python-storage@v3.9.0...v3.10.0)
(2026-03-18)

### Features

* [Bucket Encryption Enforcement] add support for bucket encryption
enforcement config (#1742)
([2a6e8b00e4e6ff57460373f8e628fd363be47811](googleapis/python-storage@2a6e8b0))

### Perf Improvments

* [Rapid Buckets Reads] Use raw proto access for read resumption
strategy (#1764)
([14cfd61ce35365a409650981239ef742cdf375fb](googleapis/python-storage@14cfd61))
* [Rapid Buckets Benchmarks] init mp pool & grpc client once, use
os.sched_setaffinity (#1751)
([a9eb82c1b9b3c6ae5717d47b76284ed0deb5f769](googleapis/python-storage@a9eb82c))
* [Rapid Buckets Writes] don't flush at every append, results in bad
perf (#1746)
([ab62d728ac7d7be3c4fe9a99d72e35ead310805a](googleapis/python-storage@ab62d72))


### Bug Fixes

* [Windows] skip downloading blobs whose name contain `":" ` eg: `C:`
`D:` etc when application runs in Windows. (#1774)
([558198823ed51918db9c0137715d1e7f5b593975](googleapis/python-storage@5581988))
* [Path Traversal] Prevent path traversal in `download_many_to_path`
(#1768)
([700fec3bf7aa37bd5ea4b163cc3f9e8e6892bd5a](googleapis/python-storage@700fec3))
* [Rapid Buckets] pass token correctly, '&' instead of ',' (#1756)
([d8dd1e074d2431de9b45e0103181dce749a447a0](googleapis/python-storage@d8dd1e0))


</details>