BC: drop support for conda

[jkowalleck]

https://docs.conda.io/en/latest/

Conda provides package, dependency, and environment management for any language. The following documentation site provides all you need to get started with leveraging the power of conda.

Since conda is not a package manager for python, but something different (that utilizes python), it is considered to be out of scope of this project.

the conda SBOM feature could be an independent project, an own conda-plugin.
see also: #594
conda plugins may be written in many languages. CycloneDX does have a library available in many languages (see "library" in https://cyclonedx.org/tool-center/).
some are even available in a conda repo: https://anaconda.org/conda-forge/cyclonedx-python-lib

feel free to write a plugin for conda.
Reach out to project leaders (see here),
if you want to publish the plugin under the OWASP/CycloneDX umbrella: https://github.com/CycloneDX/cyclonedx-conda

[jkowalleck]

fixed by #605

[jkowalleck]

This feature will be part of the next/upcoming major release.
Changelog: see #605
Install via: pip install cyclonedx-bom==4.0.0rc1