docker: use commit ref to bump cabana docker build step

Dockerfile

@@ -1,5 +1,7 @@
 FROM node:16-alpine AS cabana
 
+ENV CABANA_REF="bc1a174d8c47b3759fa07da00fc49824d8e2b029"
+
 RUN apk update && \
     apk add --no-cache git
 
@@ -7,6 +9,8 @@ RUN git clone https://github.com/RetroPilot/cabana.git
 
 WORKDIR /cabana
 
+RUN git checkout $CABANA_REF
+
 RUN yarn install && \
     yarn netlify-sass && \
     yarn build