Add esp32-c3 to build workflow

Author: CapnBry

.github/workflows/build.yaml

@@ -56,6 +56,7 @@ jobs:
           - olimex_esp32-poe-iso
           - heltec_esp32-wifi-lora-v2
           - wt32-eth01
+          - esp32-c3-devkitc-02
         gui:
           - name: gui-v2
             repo: OpenEVSE/openevse-gui-v2