Switch package signing key after releasing fluent-package v5 series.
Fluentd developers (Fluent Package Official Signing Key)
B40948B6A3B80E90F40E841F977D7A0943FA320E
Background
When releasing fluent-package v5.0.0, v5.0.1, we still use with old signing key because existing td-agent user can upgrade by
even though manually editing apt-line fluentd.sources.
Problem
Currently, we can't switch signing key yet.
Expected
Switch package signing key after releasing fluent-package v5 series.
Fluentd developers (Fluent Package Official Signing Key) B40948B6A3B80E90F40E841F977D7A0943FA320E
Background
When releasing fluent-package v5.0.0, v5.0.1, we still use with old signing key because existing td-agent user can upgrade by even though manually editing apt-line fluentd.sources.
https://github.com/fluent/fluent-package-builder/blob/master/fluent-package/manage-fluent-repositories.sh#L36
So switching signing key affects only existing td-agent users who manually point to fluent-package apt line.