Use newer python

.github/workflows/validate_python.yml

@@ -4,15 +4,9 @@ name: Validate Python (flake8)
 # yamllint disable-line rule:truthy
 on:
   push:
-    branches:
-      - dev
-      - beta
     paths:
       - '*.py'
   pull_request:
-    branches:
-      - dev
-      - beta
     paths:
       - '*.py'
   workflow_dispatch:
@@ -24,7 +18,7 @@ jobs:
       - name: Setup Python
         uses: actions/setup-python@v1
         with:
-          python-version: 3.7.4
+          python-version: 3.7.17
           architecture: x64
       - name: Checkout PyTorch
         uses: actions/checkout@main