Pin espressif32 to v3.5.0 until LMIC supports 4.1.0

The new espressif32 v4.1.0 is out, which is good, but several libraries are no longer compatible with this code.
MCCI LMIC might also need updates to build.

This update pins the version of espressif32 to 3.5.0 so PlatformIO won't upgrade to the newest one.
Also pinning the library versions, just in case.

platformio.ini

@@ -12,7 +12,7 @@
 src_dir = main
 
 [env]
-platform = espressif32
+platform = espressif32@^3.5.0
 board = ttgo-t-beam
 framework = arduino
 build_flags = -Wall
@@ -25,10 +25,10 @@ build_flags = -Wall
 	-D ARDUINO_TTGO_LoRa32_V1
 
 lib_deps = 
-	mcci-catena/MCCI LoRaWAN LMIC library
-	thingpulse/ESP8266 and ESP32 OLED driver for SSD1306 displays
-	lewisxhe/AXP202X_Library
-	mikalhart/TinyGPSPlus
+	mcci-catena/MCCI LoRaWAN LMIC library@^4.1.1
+	thingpulse/ESP8266 and ESP32 OLED driver for SSD1306 displays@^4.3.0
+	lewisxhe/AXP202X_Library@^1.1.3
+	mikalhart/TinyGPSPlus@^1.0.3
 
 monitor_speed = 115200
 ; monitor_port = COM17