This is missing in the CentOS 9 repositories for some reason. Download
it directly from the build system until this can be fixed.

The older versions are getting deprecated, so make the switch.

This is needed to correctly handle the spec file, so it needs to be
installed before we parse it for build dependencies.

We do all the prep work in the image step for the other targets, so
let's do the same here.

This is a build requirement, not a fundamental system thing, so it
should not be handled here.

The image has been updated, so this workaround is no longer needed.

We want it to complain loudly if a dependency is missing, not just
quietly continue on.

It is generally pulled in as a requirement from GnuTLS, but let's be
explicitly now that we make use of nettle directly.

Might be useful for testing in some cases. Note that the Windows and
Linux binaries will depend on libraries from the build environment. So
the user will need to match those manually.

CentOS 8 is EOL and is now replaced with CentOS Stream 8.

This images isn't available on Docker Hub unfortunately, so we grab it
from Quay.

Linux implementation using ffmpeg

It's difficult to support both old and new versions, so raise the
requirement to the oldest that is commonly used, which is CMake 3.10.2
on Ubuntu 18.04.

This version of Ubuntu is no longer fully supported so let's stop caring
about builds there.

Travis has unfortunately been severely rate limited by Docker Hub so we
have to switch to GitHub, which has an agreement with Docker to avoid
the rate limiting.

A initial workflow needs to be defined for actions to trigger on pull
requests, so just add a minimal, dummy one.

So that people can easily find them and not file bug reports for
things that are just questions.

We want users to use the templates so we don't miss any relevant
information.

Add basic templates for users to follow so that we get the information
we need directly in the initial report.