The release manager handles all releases
Establish ownership of security releases
Explicitly mention patch releases
Merge branch 'security-release-ownership' into 'master'

Security release ownership

We saw the following problems around the 7.4.4 release:

- the fix got merged into master while it should have been held back
- there was a security fix but no release manager to release it

With this change we want to improve our process and documentation
to prevent situations like this in the future.

See merge request !1273