🚨 Cleaner errors for renamed envs (#23690)

ini/renamed.ini

+#
+# Marlin Firmware
+# PlatformIO Configuration File
+#
+
+#################################
+#                               #
+#     Renamed Environments      #
+#                               #
+#################################
+
+#
+# List of environment names that are no longer used
+#
+
+[env:STM32F103RET6_creality_maple]
+extends = env:STM32F103RE_maple
+
+[env:STM32F103RET6_creality]
+extends = STM32F103Rx_creality
+board   = genericSTM32F103RE
+
+[env:STM32F103RET6_creality_xfer]
+extends = STM32F103Rx_creality_xfer
+board   = genericSTM32F103RE

platformio.ini

     ini/stm32h7.ini
     ini/stm32g0.ini
     ini/teensy.ini
+    ini/renamed.ini
 
 #
 # The 'common' section applies to most Marlin builds.