Always exclude range test

Range test is excluded on every target as of 2.8, so set
MESHTASTIC_EXCLUDE_RANGETEST=1 globally in [env] build_flags and drop the
now-redundant per-variant flags from esp32, rak11200 and stm32.

Guard RangeTestModule.cpp with the same condition used in Modules.cpp so the
translation unit compiles to nothing rather than relying on --gc-sections to
strip it, and always report RANGETEST_CONFIG in the device metadata
excluded_modules bitmask so clients hide the config.

src/modules/RangeTestModule.cpp

@@ -8,15 +8,16 @@
  * The RangeTestModule class is an OSThread that runs the module.
  * The RangeTestModuleRadio class handles sending and receiving packets.
  */
-#include "RangeTestModule.h"
+#include "configuration.h"
+#if !MESHTASTIC_EXCLUDE_RANGETEST && !MESHTASTIC_EXCLUDE_GPS
 #include "FSCommon.h"
 #include "MeshService.h"
 #include "NodeDB.h"
 #include "PowerFSM.h"
+#include "RangeTestModule.h"
 #include "Router.h"
 #include "SPILock.h"
 #include "airtime.h"
-#include "configuration.h"
 #include "gps/GeoCoord.h"
 #include "gps/RTC.h"
 #include <Arduino.h>
@@ -353,3 +354,5 @@ bool RangeTestModuleRadio::removeFile()
     return 0;
 #endif
 }
+
+#endif // !MESHTASTIC_EXCLUDE_RANGETEST && !MESHTASTIC_EXCLUDE_GPS