waf: require python 3.8.0 or later

for 4.5.x we no longer support py2

Tools/ardupilotwaf/dronecangen.py

@@ -66,9 +66,6 @@ def configure(cfg):
     """
     setup environment for uavcan header generator
     """
-    cfg.load('python')
-    cfg.check_python_version(minver=(2,7,0))
-
     env = cfg.env
     env.DC_DSDL_COMPILER_DIR = cfg.srcnode.make_node('modules/DroneCAN/dronecan_dsdlc/').abspath()
     env.DC_DSDL_COMPILER = env.DC_DSDL_COMPILER_DIR + '/dronecan_dsdlc.py'

Tools/ardupilotwaf/mavgen.py

@@ -94,8 +94,5 @@ def configure(cfg):
     """
     setup environment for mavlink header generator
     """
-    cfg.load('python')
-    cfg.check_python_version(minver=(2,7,0))
-
     env = cfg.env
     env.MAVLINK_DIR = cfg.srcnode.make_node('modules/mavlink/').abspath()

wscript

@@ -475,6 +475,10 @@ def configure(cfg):
         # also in env for hrt.c
         cfg.env.AP_BOARD_START_TIME = cfg.options.board_start_time
 
+    # require python 3.8.x or later
+    cfg.load('python')
+    cfg.check_python_version(minver=(3,8,0))
+
     cfg.load('ap_library')
 
     cfg.msg('Setting board to', cfg.options.board)