deps: Update actions/setup-python action to v5 (#120)

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This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [actions/setup-python](https://togithub.com/actions/setup-python) |
action | major | `v4.8.0` -> `v5.0.0` |

---

### Release Notes

<details>
<summary>actions/setup-python (actions/setup-python)</summary>

###
[`v5.0.0`](https://togithub.com/actions/setup-python/releases/tag/v5.0.0)

[Compare
Source](https://togithub.com/actions/setup-python/compare/v4.8.0...v5.0.0)

#### What's Changed

In scope of this release, we update node version runtime from node16 to
node20
([actions/setup-python#772).
Besides, we update dependencies to the latest versions.

**Full Changelog**:
actions/setup-python@v4.8.0...v5.0.0

</details>

---

### Configuration

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Automerge - At any time (no schedule defined).

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are satisfied.

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🔕 **Ignore**: Close this PR and you won't be reminded about this update
again.

---

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Co-authored-by: Averi Kitsch <akitsch@google.com>

.github/workflows/tests.yml

@@ -72,7 +72,7 @@ jobs:
           token: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Setup Python
-        uses: actions/setup-python@b64ffcaf5b410884ad320a9cfac8866006a109aa # v4.8.0
+        uses: actions/setup-python@0a5c61591373683505ea898e09a3ea4f39ef2b9c # v5.0.0
         with:
           python-version: "3.11"