chore(ci): bump GitHub Actions to Node 24 (#25)

## Summary

Bulk SHA-pin update of GitHub Actions to their latest Node-24-compatible
release. Pre-emptive migration ahead of GitHub Actions runner Node 20
removal in Fall 2026.

## Actions bumped

- `actions/checkout@v4.3.0` → `df4cb1c0…` (v6.0.3)
- `actions/setup-python@v5.6.0` → `a309ff8b…` (v6.2.0)
- `actions/upload-artifact@v4.6.2` → `043fb46d…` (v7.0.1)

## Verification

Every emitted SHA was verified via `gh api
/repos/<owner>/<repo>/commits/<sha>` before commit.

## Background

Node 20 is being removed from GitHub Actions runners in Fall 2026 (see
[GitHub
changelog](https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/)).
This PR pre-emptively bumps every pinned third-party action to its first
Node-24-compatible release so the workflows keep running on the new
runner default.

Author: shanesavoie

.github/workflows/release-test.yml

@@ -12,10 +12,10 @@ jobs:
           egress-policy: block
           policy: global-allowed-endpoints-policy
 
-      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
 
       - name: Set up Python 3.10
-        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: '3.10'
 

.github/workflows/release.yml

@@ -43,10 +43,10 @@ jobs:
           egress-policy: block
           policy: global-allowed-endpoints-policy
 
-      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
 
       - name: Set up Python
-        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: '3.10'
 
@@ -68,7 +68,7 @@ jobs:
         run: twine upload dist/*
 
       - name: Upload build artifacts for release
-        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
         with:
           name: python-package-distributions
           path: dist/