Обновляемся до composer 2 на ubuntu

 https://coderteam.ru/blog/obnovlyaemsya-do-composer-2-na-ubuntu/

Краткая выдержка

#!/bin/sh

EXPECTED_CHECKSUM="$(wget -q -O - https://composer.github.io/installer.sig)"
php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
ACTUAL_CHECKSUM="$(php -r "echo hash_file('sha384', 'composer-setup.php');")"

if [ "$EXPECTED_CHECKSUM" != "$ACTUAL_CHECKSUM" ]
then
    >&2 echo 'ERROR: Invalid installer checksum'
    rm composer-setup.php
    exit 1
fi

php composer-setup.php --quiet --install-dir /usr/bin --filename composer
RESULT=$?
rm composer-setup.php
exit $RESULT