Use esptoolpy v3.1 by default

Resolve platformio#569

Author: valeros

platform.json

@@ -111,8 +111,7 @@
     "tool-esptoolpy": {
       "type": "uploader",
       "owner": "platformio",
-      "version": "~1.30000.0",
-      "optionalVersions": ["~1.30100.0"]
+      "version": "~1.30100.0"
     },
     "tool-mbctool": {
       "optional": true,

platform.py

@@ -41,7 +41,6 @@ def configure_default_packages(self, variables, targets):
                 elif p in ("tool-mconf", "tool-idf") and "windows" in get_systype():
                     self.packages[p]["optional"] = False
             self.packages["toolchain-xtensa32"]["version"] = "~2.80400.0"
-            self.packages["tool-esptoolpy"]["version"] = "~1.30100.0"
             if "arduino" in frameworks:
                 # Arduino component is not compatible with ESP-IDF >=4.1
                 self.packages["framework-espidf"]["version"] = "~3.40001.0"