CI/CD: some latest releases added.

/misc/docker/:
+ debian 11 (i386+amd64) added,
+ fedora 32 added,
+ fedora 33 added,
+ fedora 34 added,
+ opensuse 15.2 added,
+ opensuse 15.3 added,
+ ubuntu 20.04 added,
+ ubuntu 20.10 added,
+ ubuntu 21.04 added,
- ubuntu 19.10 removed.

/.gitlab-ci.yml:
+ stages 'image' and 'build' updated.