chore: update Dockerfile for improved build process and functionality

- Add bash to the builder stage for enhanced scripting capabilities.
- Change the base image for the runner stage to gcr.io/distroless/static-debian12 for better compatibility.
- Ensure CGO is disabled during the build for a more efficient binary.

Author: theboringhumane

server/Dockerfile

@@ -2,15 +2,17 @@ FROM golang:1.24.0-alpine AS builder
 
 WORKDIR /app
 
+RUN apk add --no-cache bash
+
 COPY . .
 
-RUN go build -ldflags="-s -w" -o rabbit.go main.go
+RUN CGO_ENABLED=0 go build -ldflags="-s -w" -o rabbit.go main.go
 
-FROM debian:12 AS runner
+FROM gcr.io/distroless/static-debian12 AS runner
 
 COPY --from=builder /app/rabbit.go /usr/local/bin/rabbit.go
 COPY --from=builder /app/internal/database/migrations.sql /usr/local/bin/internal/database/migrations.sql
-RUN apk add --no-cache net-tools
+COPY --from=builder /bin/bash /bin/bash
 
 # 9999 is the tunnel server port
 # 3422 is the API port (never expose this port to the internet)