Migrate to snakeyaml-engine

[gesellix]

See https://bitbucket.org/snakeyaml/snakeyaml-engine/src/master/
and https://bitbucket.org/snakeyaml/snakeyaml/issues/561/cve-2022-1471-vulnerability-in#comment-64565202

We may have to consider support for YAML 1.1 (https://bitbucket.org/snakeyaml/snakeyaml) and YAML 1.2 (https://bitbucket.org/snakeyaml/snakeyaml-engine). Docker Compose supports YAML 1.1, newer releases might already support YAML 1.2?