infra: add zstd to the standard-5.0 image

[AbeCoull]

Issue #, if available:

Description of changes:
This changes add in the zstd package, a common compression package, to the 5.0 image.

This can also be considered for other images.

Package info:

yum info zstd
Loaded plugins: priorities
934 packages excluded due to repository priority protections
Available Packages
Name        : zstd
Arch        : x86_64
Version     : 1.5.5
Release     : 1.amzn2.0.1
Size        : 455 k
Repo        : amzn2-core/x86_64
Summary     : Zstd compression library
URL         : https://github.com/facebook/zstd
License     : BSD and GPLv2
Description : Zstd, short for Zstandard, is a fast lossless compression algorithm,
            : targeting real-time compression scenarios at zlib-level compression ratio.

Testing done:

git clone git@github.com:math411/aws-codebuild-docker-images.git
cd aws-codebuild-docker-images
git checkout patch-1
cd ubuntu/standard/5.0
docker build -t aws/codebuild/standard:5.0 .
docker run -it --entrypoint sh aws/codebuild/standard:5.0 -c bash

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