InfiniSim PR https://github.com/InfiniTimeOrg/InfiniSim/pull/10 adds
support for screenshots in png/bmp format using `libpng` submodule.
This new submodule must be added to the lv_sim workflow as well.

use InfiniSim repo to build simulator in CI

Rather than using generator-specific build commands (ex. `make` or `ninja`), the CI build now uses `cmake --build` for a more modern, best practices approach.

By switching the CI/CD workflow to use CMake's `ninja` backend, the build time goes down considerably (~4.5 minutes to ~2) compared to GNU Make

The recovery image "it is the last chance before a brick",
as described in https://github.com/InfiniTimeOrg/InfiniTime/issues/742#issuecomment-943665960

So just build it to make sure it doesn't silently break, but don't upload it.

The documentation https://github.com/JF002/InfiniTime/blob/develop/doc/contribute.md#how-to-submit-a-pull-request-
tells us to make pull requests against `develop` branch.
Update the CI to run on those pull requests to have a check if the PR breaks something unintentionally.

When installing Cmake you get Error: The add-path command is deprecated and will be disabled on November 16th...
And the file pinetime-mcuboot-app-dfu.zip was being generated as pinetime-mcuboot-app-dfu.zip.zip