Bump actions/setup-python from 4 to 6

Bumps [actions/setup-python](https://github.com/actions/setup-python) from 4 to 6.
- [Release notes](https://github.com/actions/setup-python/releases)
- [Commits](actions/setup-python@v4...v6)

---
updated-dependencies:
- dependency-name: actions/setup-python
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci-testing.yml

@@ -22,7 +22,7 @@ jobs:
         model: [ yolov5n ]
     steps:
       - uses: actions/checkout@v3
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
       #- name: Cache pip
@@ -76,7 +76,7 @@ jobs:
             torch: '1.7.0'  # min torch version CI https://pypi.org/project/torchvision/
     steps:
       - uses: actions/checkout@v3
-      - uses: actions/setup-python@v4
+      - uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
       - name: Get cache dir