CI: Fix Python linter on Github

Closes https://github.com/espressif/esp-idf/pull/8366

.github/workflows/python_lint.yml

@@ -5,7 +5,6 @@ on:
   pull_request:
     paths:
       - "**.py"
-      - "requirements.txt"
 
 jobs:
   python_lint:
@@ -13,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.6, 3.7, 3.8]
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
 
     steps:
       - name: Checkout
@@ -22,11 +21,6 @@ jobs:
         uses: actions/setup-python@master
         with:
           python-version: ${{ matrix.python-version }}
-      - name: Install dependencies
-        run: |
-          export IDF_PATH=${GITHUB_WORKSPACE}
-          pip install --upgrade pip
-          pip install -r requirements.txt
       - name: Lint with flake8
         run: |
           pip install flake8