Revert "TARGETARCH cannot have a default value, and set GOARCH simila…

…rly (#1014)"

This reverts commit 2ee9658.

src/otelcollector/Dockerfile

@@ -3,14 +3,14 @@
 
 FROM golang:latest as build
 
-ARG TARGETARCH
+ARG TARGETARCH=arm64
 ARG BUILDER_VERSION=0.81.0
 
 RUN curl -L -o /builder https://github.com/open-telemetry/opentelemetry-collector/releases/download/cmd%2Fbuilder%2Fv${BUILDER_VERSION}/ocb_${BUILDER_VERSION}_linux_${TARGETARCH}
 RUN chmod +x /builder
 WORKDIR /build
 COPY ./src/otelcollector/manifest.yml ./
-ENV GOARCH=$TARGETARCH
+ENV GOARCH=arm64
 ENV CGO_ENABLED=0
 RUN /builder --config ./manifest.yml --output-path /build/_build
 RUN ls /build/_build