Move to public ECR for DockerFile

In this commit, we are updating the Dockerfile to use python3.11 and rust1.75 images to build the ADOT Python Instrumentation image vended by this repo. This should be a no-op as a) the public ECRs should be mirrors of the DockerHub equivalent and b) these images are only used in the build process, not the final produced image (which is built from `scratch`).

Author: thpierce

Dockerfile

@@ -5,7 +5,7 @@
 #   update the `PYTHONPATH` environment variable accordingly. Then in the second stage, copy the directory to `/autoinstrumentation`.
 
 # Stage 1: Install ADOT Python in the /operator-build folder
-FROM python:3.11 AS build
+FROM public.ecr.aws/docker/library/python:3.11 AS build
 
 WORKDIR /operator-build
 
@@ -21,7 +21,7 @@ RUN sed -i "/opentelemetry-exporter-otlp-proto-grpc/d" ./aws-opentelemetry-distr
 RUN mkdir workspace && pip install --target workspace ./aws-opentelemetry-distro
 
 # Stage 2: Build the cp-utility binary
-FROM rust:1.75 as builder
+FROM public.ecr.aws/docker/library/rust:1.75 as builder
 
 WORKDIR /usr/src/cp-utility
 COPY ./tools/cp-utility .