chore(deps): update actions/setup-python action to v6 (#1632)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
|
[actions/setup-python](https://redirect.github.com/actions/setup-python)
| action | major | `v5` -> `v6` |

---

### Release Notes

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

###
[`v6`](https://redirect.github.com/actions/setup-python/compare/v5...v6)

[Compare
Source](https://redirect.github.com/actions/setup-python/compare/v5...v6)

</details>

---

### Configuration

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are satisfied.

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rebase/retry checkbox.

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

---

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---

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.github/workflows/charts_lint-test.yaml

@@ -20,7 +20,7 @@ jobs:
         with:
           version: v3.8.1
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: 3.13
 

.github/workflows/charts_test-bazel-remote.yaml

@@ -20,7 +20,7 @@ jobs:
         with:
           version: v3.8.1
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: 3.13
 

.github/workflows/charts_test-prow.yaml

@@ -20,7 +20,7 @@ jobs:
         with:
           version: v3.8.1
 
-      - uses: actions/setup-python@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: 3.13