Test PR: malloc attributes - #4

Reference:  ci: Integrate Membrowse to PR flow. [7ff4c32]
Comparison: py/gc: Annotate allocators with gcc attributes. [merge of 402053a]
  mpy-cross:  -288 -0.076% 
   bare-arm:    +0 +0.000% 
minimal x86:    +0 +0.000% 
   unix x64:    +0 +0.000% standard
      stm32:    +0 +0.000% PYBV10
     mimxrt:    +0 +0.000% TEENSY40
        rp2:    +0 +0.000% RPI_PICO_W
       samd:    +0 +0.000% ADAFRUIT_ITSYBITSY_M4_EXPRESS
  qemu rv32:   +16 +0.004% VIRT_RV32