It doesn't work since 2023-11-18. The uploading succeeds, but the
website says:

> The Coverity Build tool version is no longer supported. Please
> download the latest version for your platform from
> https://scan.coverity.com/download...

It seems, some specific toolset is installed in the
`tarantool/testing:debian-buster` image and it was deprecated 11 months
ago.

Recently the CI workflow starts to fail due to use of the old image with
an old CMake in it:

> [  2%] Performing configure step for 'bundled-nanoarrow-project'
> -- Building using CMake version: 3.13.4
> -- Configuring incomplete, errors occurred!
> CMake Error at CMakeLists.txt:19 (cmake_minimum_required):
>   CMake 3.14 or higher is required.  You are running version 3.13.4

It is likely due to commit 49c160c28c97 ("third_party: initial import of
nanoarrow").

Here I refine the workflow file:

* Get rid of the custom docker image with preinstalled Coverity toolset.
* Use a nice unofficial-coverity-scan GitHub Acti...