RP2040: Fix removal of idle_task_static_memory.c (#935)

Co-authored-by: Rahul Kar <118818625+kar-rahul-aws@users.noreply.github.com>
diff --git a/portable/CMakeLists.txt b/portable/CMakeLists.txt
index b84b301..dea052d 100644
--- a/portable/CMakeLists.txt
+++ b/portable/CMakeLists.txt
@@ -81,7 +81,6 @@
 
     # ARMv6-M / Cortex-M0 Raspberry PI RP2040 port for GCC
     $<$<STREQUAL:${FREERTOS_PORT},GCC_RP2040>:
-        ThirdParty/GCC/RP2040/idle_task_static_memory.c
         ThirdParty/GCC/RP2040/port.c>
 
     # ARMv7-M ports for GCC