Pin Docker image python:3.10-alpine

--platform=$BUILDPLATFORM
->
python:3.10-alpine@sha256:c9d3c11e89887c82efeb4f4fee8771a406cf42f41aebbd23148906d5fe3c1426

 [atomist:generated]
 [atomist-skill:atomist/docker-base-image-policy]

Signed-off-by: Atomist Bot <bot@atomist.com>

nginx-flask-mongo/flask/Dockerfile

@@ -1,5 +1,5 @@
 # syntax=docker/dockerfile:1.4
-FROM --platform=$BUILDPLATFORM python:3.10-alpine AS builder
+FROM --platform=$BUILDPLATFORM python:3.10-alpine@sha256:c9d3c11e89887c82efeb4f4fee8771a406cf42f41aebbd23148906d5fe3c1426 AS builder
 
 WORKDIR /src
 COPY requirements.txt /src

react-rust-postgres/backend/Dockerfile

@@ -1,5 +1,5 @@
 # syntax=docker/dockerfile:1.4
-FROM rust:buster@sha256:f5da153862af6a25fcf49dde3cb19b5b513f78bc00e317eb64e898a66af2881d AS base
+FROM rust:buster AS base
 
 ENV USER=root
 ENV ROCKET_ADDRESS=0.0.0.0
@@ -38,7 +38,7 @@ FROM base AS builder
 
 RUN cargo build --release --offline
 
-FROM debian:buster-slim@sha256:557ee531b81ce380d012d83b7bb56211572e5d6088d3e21a3caef7d7ed7f718b
+FROM debian:buster-slim
 
 ENV ROCKET_ENV=production