update dockerfile: no longer build on run

Dockerfile

@@ -1,10 +1,10 @@
-FROM rust:1.81
+FROM rust:1.81 AS builder
 WORKDIR /usr/src/bot
 COPY . .
 
-# FROM ubuntu:24.10
+RUN cargo --install --path .
-# COPY --from=builder /usr/local/cargo/bin/bot /usr/local/bin/bot
 
-# temporary fix for slow cross compile builds.
+FROM ubuntu:24.10
-# this will simply compile and run the code on `docker run`
+COPY --from=builder /usr/local/cargo/bin/bot /usr/local/bin/bot
-CMD ["cargo", "run", "--release"]
+
+CMD ["bot"]