Bump arm cortex size test (#12345)

Summary:

Fix test failure after D77472917:

https://github.com/pytorch/executorch/actions/runs/16182327731/job/45681389685

Reviewed By: psiddh, BujSet

Differential Revision: D78100159

Author: lucylq

.github/workflows/trunk.yml

@@ -240,11 +240,11 @@ jobs:
 
         cxx_flags="-fno-exceptions -fno-rtti -Wall -Werror -Wno-int-in-bool-context -DET_HAVE_PREAD=0"
         setup_script_args=""
-        if [[ ${{ matrix.os}} == "bare_metal" ]]; then 
+        if [[ ${{ matrix.os}} == "bare_metal" ]]; then
           toolchain_prefix=arm-none-eabi-
-          threshold="103268" # ~100KiB
+          threshold="104000" # should be ~103.7KB, set threshold to 104KB.
           toolchain_cmake=examples/arm/ethos-u-setup/arm-none-eabi-gcc.cmake
-        elif [[ ${{ matrix.os}} == "zephyr-preset" ]]; then 
+        elif [[ ${{ matrix.os}} == "zephyr-preset" ]]; then
           setup_script_args="--target-toolchain zephyr"
           toolchain_prefix=arm-zephyr-eabi-
           threshold="133120" # should be ~125KB, set threshold to 130KB