Changes

Update the docker images used for testing PRs to 1.16 (#1217)

* Update the docker images used for testing PRs to 1.16

  - This provides more recent versions of tools like CMake. It is also
    what is currently being used by the OpenModelica repo to test its
    own PRs.

* Remove 32 bit Linux builds.

  - These are probably not used by anyone.
  - We can not upgrade the image used to test them to 1.16 like the 64
    bit but there is no v1.16 image for 32 bit yet in the OpenModelica
    docker registry.
    We can add one but there is also not pre-built 32 Linux binary for CMake
    any longer. One has to build it from source.

    So we have to create a new v1.16 32 bit image, build CMake from
    source inside it, and then make it available for testing the PRs for
    32 bit build of OMSimulator. While no one actually needs 32
    bit builds of OMSimulator to being with. So remove them now.