fix(rp2xx0): ignore iLabs_Hearth so Pico targets build again (#11757)

arduino-pico gained a bundled iLabs_Hearth library that supplies its own
Preferences.h. NodeDB.cpp includes <Preferences.h> inside an ARCH_ESP32
guard, and the library dependency finder runs in chain mode, which matches
include directives without evaluating the preprocessor. It therefore pulls
the library into every Pico build, and Hearth.cpp refuses to compile on a
board that does not define ESP_SERIAL_PORT:

  iLabs_Hearth/src/Hearth.cpp:121:2: error: #error "iLabs Hearth requires a
  board variant that defines ESP_SERIAL_PORT ..."

The library only reaches the build because the platform resolves
framework-arduinopico from an arduino-pico master commit; the
platform_packages entry here pins the name arduino-pico, which is a
different package and does not override it.

Ignoring the library is enough, since no Pico target uses Matter. The
sibling iLabs_ESP-NOW ships ESP32_NOW.h and ATLink.h, which nothing
includes, so it needs no entry.

variants/rp2040/rp2040.ini

@@ -25,6 +25,9 @@ build_src_filter =
 lib_ignore =
   BluetoothOTA
   lvgl
+  ; Ships its own Preferences.h, which the LDF matches against the ARCH_ESP32-only
+  ; include in NodeDB.cpp; compiling it then trips its own "not a Challenger" #error.
+  iLabs_Hearth
 
 lib_deps =
   ${arduino_base.lib_deps}

variants/rp2350/rp2350.ini

@@ -22,6 +22,9 @@ build_src_filter =
 lib_ignore =
   BluetoothOTA
   lvgl
+  ; Ships its own Preferences.h, which the LDF matches against the ARCH_ESP32-only
+  ; include in NodeDB.cpp; compiling it then trips its own "not a Challenger" #error.
+  iLabs_Hearth
 
 lib_deps =
   ${arduino_base.lib_deps}