add target to dockerfile

Author: lherman-cs

Dockerfile

@@ -4,8 +4,8 @@ COPY Cargo.* .
 COPY . .
 RUN --mount=type=cache,target=/volume/target \
     --mount=type=cache,target=/root/.cargo/registry \
-    cargo build --release -p pulsebeam && \
-    mv /volume/target/release/pulsebeam /volume/pulsebeam-bin
+    cargo build --target x86_64-unknown-linux-musl --release -p pulsebeam && \
+    mv /volume/target/x86_64-unknown-linux-musl/release/pulsebeam /volume/pulsebeam-bin
 
 
 FROM cgr.dev/chainguard/static