Consume device-ui as a pio library (#6193)

bin/platformio-custom.py

@@ -125,4 +125,9 @@ for flag in flags:
     
 projenv.Append(
     CCFLAGS=flags,
-)
+)
+
+for lb in env.GetLibBuilders():
+    if lb.name == "meshtastic-device-ui":
+        lb.env.Append(CPPDEFINES=[("APP_VERSION", verObj["long"])])
+        break