fa1fd07468 ci: Enable more shellcheck (MarcoFalke)
Pull request description:
shellcheck is often the main "reviewer" of CI code written in Bash, so it seems odd to disable it by putting commands into `bash -c "cmd..."`.
Fix that by removing `bash -c`, where it isn't intended and where the removal is easily possible.
ACKs for top commit:
hebasto:
ACK fa1fd07468.
Tree-SHA512: 6412dd3f8d702bca7762a8f1be3f9d2782132936fcc7ae5c31690b594e04f69708110e6f6233d5a61901289d13c7089ab5646a2c3ef2266fffc36d0543f4b7ae