Drop Python 3.6

tools/ci/setup_python.sh

@@ -4,7 +4,7 @@ if [ -z ${PYTHON_VER+x} ]; then
     # Use this version of the Python interpreter if it was not defined before.
     # 3.6.13 is the default python3 interpreter in esp32-ci-env
     # Jobs which doesn't support this version should define PYTHON_VER themselves
-    PYTHON_VER=3.6.13
+    PYTHON_VER=3.7.10
 fi
 
 if [ -f /opt/pyenv/activate ];