fix: target arch in build

Author: AndyTWF

Dockerfile

@@ -1,14 +1,16 @@
 # Base stage, sets up the GRPC Health Probe, we use a ubuntu image because no devcontainer features work on alpine
 ARG GO_VERSION
+FROM golang:${GO_VERSION} AS builder_base
+
+# Needed to get the right grpc_health_probe binary
 ARG TARGETOS
 ARG TARGETARCH
-FROM golang:${GO_VERSION} AS builder_base
 
 WORKDIR /app
 
 # Install gRPC Health Probe
 RUN set -ex \
-    && curl -fSL "https://github.com/grpc-ecosystem/grpc-health-probe/releases/download/v0.4.19/grpc_health_probe-$TARGETOS-$TARGETARCH -o /usr/local/bin/grpc_health_probe" \
+    && curl -fSL "https://github.com/grpc-ecosystem/grpc-health-probe/releases/download/v0.4.19/grpc_health_probe-${TARGETOS}-${TARGETARCH}" -o /usr/local/bin/grpc_health_probe \
     && chmod +x /usr/local/bin/grpc_health_probe
 
 #######################################################
@@ -51,7 +53,7 @@ ENTRYPOINT [ "./docker/test-container.sh" ]
 # Builds the production binary
 FROM golang:${GO_VERSION}-alpine AS builder_production
 
-WORKDIR /app 
+WORKDIR /app
 
 # Go dependencies
 COPY go.mod go.sum ./