[Zig/Httpz] update dockerfile 3

Author: Kayden1412

frameworks/Zig/httpz/httpz.dockerfile

@@ -1,6 +1,5 @@
 FROM eloitor/zig:0.13.0 AS build
 
-ARG ZIG_VER=0.13
 ENV PG_USER=benchmarkdbuser
 ENV PG_PASS=benchmarkdbpass
 ENV PG_DB=hello_world
@@ -9,7 +8,9 @@ ENV PG_PORT=5432
 
 WORKDIR /app
 
-COPY . .
+COPY src src
+COPY build.zig.zon build.zig.zon
+COPY build.zig build.zig
 
 RUN zig build -Doptimize=ReleaseFast
 
@@ -19,4 +20,6 @@ RUN apt-get update && apt-get install -y ca-certificates
 
 COPY --from=build /app/zig-out/bin/httpz /server
 
+EXPOSE 3000
+
 CMD ["/server"]