Fix rumba32 environments

Followup to #18116

platformio.ini

   SlowSoftI2CMaster=https://github.com/mikeshub/SlowSoftI2CMaster/archive/master.zip
 
 # Common traits for environments using HAL/STM32
-[common_stm32]
+[base_stm32]
 platform      = ststm32@<6.2.0
 platform_packages = framework-arduinoststm32@>=4.10700,<4.10800
 lib_deps      = ${common.lib_deps}
 lib_ignore    = SoftwareSerial
 build_flags   = ${common.build_flags}
   -IMarlin/src/HAL/STM32 -std=gnu++14
-  -DUSBCON -DUSBD_USE_CDC -DUSBD_VID=0x0483
+  -DUSBCON -DUSBD_USE_CDC
 build_unflags = -std=gnu++11
 src_filter    = ${common.default_src_filter} +<src/HAL/STM32>
 
+[common_stm32]
+platform      = ${base_stm32.platform}
+extends       = base_stm32
+build_flags   = ${base_stm32.build_flags} -DUSBD_VID=0x0483
+
 # Common traits for environments using HAL/STM32F1
 [common_stm32f1]
 platform      = ${common_stm32.platform}
 #
 # RUMBA32
 #
-[env:rumba32_f446ve]
-platform      = ${common_stm32.platform}
-extends       = common_stm32
+
+[common_rumba32]
+platform      = ${base_stm32.platform}
+extends       = base_stm32
 board         = rumba32_f446ve
-build_flags   = ${common_stm32.build_flags} -Os
-  -DSTM32F4xx -DARDUINO_RUMBA32_F446VE -DARDUINO_ARCH_STM32 "-DBOARD_NAME=\"RUMBA32_F446VE\""
-  -DSTM32F446xx "-DUSB_PRODUCT=\"RUMBA32_F446VE\""
-  -DHAL_PCD_MODULE_ENABLED
-  -DDISABLE_GENERIC_SERIALUSB
-  -DHAL_UART_MODULE_ENABLED
-monitor_speed = 500000
 upload_protocol = dfu
+monitor_speed = 500000
+
+#
+# RUMBA32 F446VE
+#
+
+[env:rumba32_f446ve]
+platform      = ${common_rumba32.platform}
+extends       = common_rumba32
+build_flags   = ${base_stm32.build_flags} -DUSBD_VID=0x0483
 
 #
 # MKS RUMBA32 (adds TMC2208/2209 UART interface and AUX-1)
 #
 [env:rumba32_mks]
-platform      = ${common_stm32.platform}
-extends       = env:rumba32_f446ve
-build_flags   = ${rumba32_f446ve.build_flags} -UUSBD_VID -DUSBD_VID=0x8000
+platform      = ${common_rumba32.platform}
+extends       = common_rumba32
+build_flags   = ${base_stm32.build_flags} -DUSBD_VID=0x8000
 
 #
 # Just print the dependency tree