Bump actions/setup-python from 4 to 5

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 4 to 5.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v4...v5)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/stage-2-test.yaml

@@ -41,7 +41,7 @@ jobs:
       - name: "Checkout code"
         uses: actions/checkout@v4
       - name: "Set up Python"
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: '3.13'
       - name: "Run unit test suite"
@@ -58,7 +58,7 @@ jobs:
       - name: "Checkout code"
         uses: actions/checkout@v4
       - name: "Set up Python"
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: '3.13'
       - name: "Run linting"
@@ -76,7 +76,7 @@ jobs:
       - name: "Checkout code"
         uses: actions/checkout@v4
       - name: "Set up Python"
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: '3.13'
       - name: "Run test coverage check"

.github/workflows/stage-4-acceptance.yaml

@@ -114,7 +114,7 @@ jobs:
       - name: "Checkout code"
         uses: actions/checkout@v4
       - name: "Set up Python"
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: '3.13'
       - name: "Run integration test"