deps: Update dependency google-auth to v2.26.1 (#163)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
|
[google-auth](https://togithub.com/googleapis/google-auth-library-python)
| `==2.25.1` -> `==2.26.1` |
[![age](https://developer.mend.io/api/mc/badges/age/pypi/google-auth/2.26.1?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
[![adoption](https://developer.mend.io/api/mc/badges/adoption/pypi/google-auth/2.26.1?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
[![passing](https://developer.mend.io/api/mc/badges/compatibility/pypi/google-auth/2.25.1/2.26.1?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|
[![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/google-auth/2.25.1/2.26.1?slim=true)](https://docs.renovatebot.com/merge-confidence/)
|

---

### Release Notes

<details>
<summary>googleapis/google-auth-library-python (google-auth)</summary>

###
[`v2.26.1`](https://togithub.com/googleapis/google-auth-library-python/blob/HEAD/CHANGELOG.md#2261-2024-01-03)

[Compare
Source](https://togithub.com/googleapis/google-auth-library-python/compare/v2.26.0...v2.26.1)

##### Bug Fixes

- Ensure that refresh worker is pickle-able.
([#&#8203;1447](https://togithub.com/googleapis/google-auth-library-python/issues/1447))
([421c184](https://togithub.com/googleapis/google-auth-library-python/commit/421c184ff4654024afe3e64754318a6be0cc96fc))

###
[`v2.26.0`](https://togithub.com/googleapis/google-auth-library-python/blob/HEAD/CHANGELOG.md#2260-2023-12-20)

[Compare
Source](https://togithub.com/googleapis/google-auth-library-python/compare/v2.25.2...v2.26.0)

##### Features

- Add optional non blocking refresh for sync auth code
([a6dc2c3](https://togithub.com/googleapis/google-auth-library-python/commit/a6dc2c336a5e76a478691e3bedd0418aae08b911))
- Add optional non blocking refresh for sync auth code
([#&#8203;1368](https://togithub.com/googleapis/google-auth-library-python/issues/1368))
([a6dc2c3](https://togithub.com/googleapis/google-auth-library-python/commit/a6dc2c336a5e76a478691e3bedd0418aae08b911))

##### Bug Fixes

- External account user cred universe domain support
([#&#8203;1437](https://togithub.com/googleapis/google-auth-library-python/issues/1437))
([75068f9](https://togithub.com/googleapis/google-auth-library-python/commit/75068f93453e6ea0b5c7be5561e7ba342c695e95))
- Guard delete statements. Add default fallback for
\_use_non_blocking_refresh.
([#&#8203;1445](https://togithub.com/googleapis/google-auth-library-python/issues/1445))
([776d634](https://togithub.com/googleapis/google-auth-library-python/commit/776d634ac6d989b224f8dbfb11d166cb3025a342))

###
[`v2.25.2`](https://togithub.com/googleapis/google-auth-library-python/blob/HEAD/CHANGELOG.md#2252-2023-12-08)

[Compare
Source](https://togithub.com/googleapis/google-auth-library-python/compare/v2.25.1...v2.25.2)

##### Bug Fixes

- Fix user cred universe domain issue
([#&#8203;1436](https://togithub.com/googleapis/google-auth-library-python/issues/1436))
([ae314a8](https://togithub.com/googleapis/google-auth-library-python/commit/ae314a8f8c63ada4e31683464c24e28df0f5af7f))

</details>

---

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langchain_tools_demo/requirements.txt

@@ -1,6 +1,6 @@
 fastapi==0.106.0
 google-cloud-aiplatform==1.38.1
-google-auth==2.25.1
+google-auth==2.26.1
 itsdangerous==2.1.2
 jinja2==3.1.2
 langchain==0.0.353