Update composer/composer Docker tag to v2.8.6 (#351)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

Dockerfile.php-cli

@@ -1,7 +1,7 @@
 # syntax=docker/dockerfile:1.1.7-experimental
 FROM lendableuk/php-fpm-alpine:8.1.16-alpine3.17 as base
 
-COPY --from=composer/composer:2.8.5-bin /composer /usr/bin/composer
+COPY --from=composer/composer:2.8.6-bin /composer /usr/bin/composer
 
 RUN apk add --no-cache git openssh \
     && mkdir -p -m 0600 ~/.ssh && ssh-keyscan github.com >> ~/.ssh/known_hosts