ci: upgrade Python from 3.8 to 3.10+ in CI workflows

Python 3.8 reached EOL in October 2024. Newer package versions
(scikit-learn>=1.8, scikit-image>=0.26, tensorboard>=2.20) no longer
support Python 3.8, causing dependabot PRs to fail CI.

- functional-test: 3.8 → 3.10
- code-lint: 3.8 → 3.10
- smoke-test: 3.8/3.9/3.10 → 3.9/3.10/3.11

Author: Pillar1989

.github/workflows/code-lint.yml

@@ -37,7 +37,7 @@ jobs:
       - name: setup python
         uses: actions/setup-python@v5
         with:
-          python-version: '3.8'
+          python-version: '3.10'
           cache: 'pip'
 
       - name: install dependencies

.github/workflows/functional-test.yml

@@ -49,7 +49,7 @@ jobs:
         os:
           - ubuntu-latest
         python-version:
-          - '3.8'
+          - '3.10'
         task:
           - classification
           - detection

.github/workflows/smoke-test.yml

@@ -34,9 +34,9 @@ jobs:
           - ubuntu-latest
           - windows-latest
         python-version:
-          - '3.8'
           - '3.9'
           - '3.10'
+          - '3.11'
     defaults:
       run:
         shell: bash -l {0}