make platformio.ini even more modular

arch/portduino/portduino.ini

@@ -0,0 +1,19 @@
+; The Portduino based sim environment on top of any host OS, all hardware will be simulated
+[portduino_base]
+build_src_filter = 
+  ${env.build_src_filter} 
+  -<platform/esp32/> 
+  -<nimble/> 
+  -<platform/nrf52/> 
+  -<platform/stm32wl/> 
+  -<platform/rp2040>
+  -<mesh/http/> 
+  -<modules/esp32>
+  -<modules/Telemetry>
+  +<../variants/portduino>
+lib_deps =
+  ${env.lib_deps}
+  ${networking_base.lib_deps}
+  rweather/Crypto
+  https://github.com/meshtastic/RadioLib.git#5582ac30578ff3f53f20630a00b2a8a4b8f92c74
+build_flags = ${arduino_base.build_flags} -Isrc/platform/portduino