Revert "[libretiny] Set lib_compat_mode to soft for libretiny (#9439)"

This reverts commit f4ac951b15.

esphome/components/libretiny/__init__.py

@@ -268,7 +268,7 @@ async def component_to_code(config):
 
     # disable library compatibility checks
     cg.add_platformio_option("lib_ldf_mode", "off")
-    cg.add_platformio_option("lib_compat_mode", "soft")
+    cg.add_platformio_option("lib_compat_mode", "strict")
     # include <Arduino.h> in every file
     cg.add_platformio_option("build_src_flags", "-include Arduino.h")
     # dummy version code

platformio.ini

@@ -212,7 +212,6 @@ build_unflags =
 extends = common:arduino
 platform = libretiny@1.9.1
 framework = arduino
-lib_compat_mode = soft
 lib_deps =
     droscy/esp_wireguard@0.4.2    ; wireguard
 build_flags =