Update Arduino core to v2.0.15

Resolve platformio#1354

Author: valeros

platform.json

@@ -82,14 +82,14 @@
       "type": "framework",
       "optional": true,
       "owner": "platformio",
-      "version": "~3.20014.0"
+      "version": "~3.20015.0"
     },
     "framework-espidf": {
       "type": "framework",
       "optional": true,
       "owner": "platformio",
       "version": "~3.50201.0",
-      "optionalVersions": ["~3.40406.0"]
+      "optionalVersions": ["~3.40407.0"]
     },
     "tool-esptoolpy": {
       "type": "uploader",

platform.py

@@ -113,7 +113,7 @@ def configure_default_packages(self, variables, targets):
 
             if "arduino" in frameworks:
                 # Downgrade the IDF version for mixed Arduino+IDF projects
-                self.packages["framework-espidf"]["version"] = "~3.40406.0"
+                self.packages["framework-espidf"]["version"] = "~3.40407.0"
                 # Delete the latest toolchain packages from config
                 self.packages.pop("toolchain-xtensa-esp-elf", None)
             else: