Use ststm32@~12.1

ini/stm32f1.ini

 # HAL/STM32 Base Environment values
 #
 [common_stm32]
-platform      = ststm32@~12.0
+platform      = ststm32@~12.1
 build_flags   = ${common.build_flags}
   -std=gnu++14
   -DUSBCON -DUSBD_USE_CDC
 # HAL/STM32F1 Common Environment values
 #
 [common_stm32f1]
-platform          = ststm32@~12.0
+platform          = ststm32@~12.1
 board_build.core  = maple
 build_flags       = !python Marlin/src/HAL/STM32F1/build_flags.py
   ${common.build_flags}