Remove code for unnecessary Adafruit SAMD Boards platform dependency (adafruit#76)

Adafruit SAMD Boards doesn't have a dependency on Arduino SAMD Boards, so this only slows down the CI run.

Author: per1234

build_platform.py

@@ -111,8 +111,6 @@ def print_bold(message, end = '\n'):
 
 def install_platform(platform):
     print("Installing", platform, end=" ")
-    if platform == "adafruit:samd":   # we have a platform dep
-        install_platform("arduino:samd")
     if platform == "adafruit:avr":   # we have a platform dep
         install_platform("arduino:avr")
     if os.system("arduino-cli core install "+platform+" --additional-urls "+BSP_URLS+" > /dev/null") != 0: