github/workflows: Run code size workflow on shared or port code changes.

To get more insight to firmware size changes when code changes.

Signed-off-by: Damien George <damien@micropython.org>

.github/workflows/code_size.yml

@@ -8,9 +8,15 @@ on:
       - 'tools/**'
       - 'py/**'
       - 'extmod/**'
+      - 'shared/**'
       - 'lib/**'
       - 'ports/bare-arm/**'
+      - 'ports/mimxrt/**'
       - 'ports/minimal/**'
+      - 'ports/rp2/**'
+      - 'ports/samd/**'
+      - 'ports/stm32/**'
+      - 'ports/unix/**'
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}