Fix CI

Author: hasumikin

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
         git apply < ../../.github/workflows/rp2040js.patch || echo "Patch may already be applied"
         npm install
         popd
-    - run: rake mrubyc:pico:debug
+    - run: rake picoruby:pico:debug
     - run: |
         set -eux
         npm --prefix ./lib/rp2040js run start:micropython -- --image $PWD/build/picoruby/pico/R2P2_PICO-FLASH*.uf2 | tee log.txt &