ci: clean workspace on self-hosted runners

Added 'tarantool/actions/cleanup' action to each job which uses
self-hosted runners.

The action cleans workspace directory of self-hosted runner after
previous run. The main reason to add this action is 'Need a single
revision' error [1] caused by a conflict of submodule versions,
the standard 'actions/checkout' action fails with this error. It's a
well-known problem and related issue [2] is still opened.

[1] https://github.com/tarantool/tarantool-qa/issues/145
[2] https://github.com/actions/checkout/issues/418

NO_DOC=ci
NO_TEST=ci
NO_CHANGELOG=ci

Closes tarantool/tarantool-qa#145