feat: add missing build-time SBOMs

[dervoeti]

Description

Fix needed for https://github.com/stackabletech/issues/issues/614

Changes:

• Changed some RUN commands to Heredoc
• Break circular dependencies in the Airflow SBOM by removing the dependencies from the providers on Airflow itself. For example, in the current SBOM, apache-airflow-providers-smtp depends on apache-airflow and apache-airflow depends on apache-airflow-providers-smtp. This causes the rendering of the dependency tree in SecObserve to fail.
• Create an SBOM for Kafka. It took a while to figure out how to not include all the integration tests in the SBOM, this was the only working solution I found.
• Generate build-time SBOMs for OPA and statsd_exporter. I had to create a dummy Git repo with a dummy commit that's tagged with the version of OPA / statsd_exporter, because that's how cyclonedx-gomod (and I think Go in general) determines the version at build time. I did not find another way, I checked the source code of cyclonedx-gomod, that seems to be the only valid way. Since we don't include the .git folder in our .tar.gz archives in Nexus, a dummy Git repo has to be created.

- [x] Changes are OpenShift compatible
- [x] All added packages (via microdnf or otherwise) have a comment on why they are added
- [x] Things not downloaded from Red Hat repositories should be mirrored in the Stackable repository and downloaded from there
- [x] All packages should have (if available) signatures/hashes verified
- [ ] Add an entry to the CHANGELOG.md file
- [ ] Integration tests ran successfully

[dervoeti]

@siegfriedweber Thanks for the review so far, that was very helpful. I should have checked things more thoroughly, sorry, will do better next time. I now also pinned the versions of s3fs and cyclonedx-bom to the current versions, they were not pinned before, which means the latest version gets installed (for example version 5.0.0 of cyclonedx-bom came out 19 hours ago and got installed right away).

[lfrancke]

Sorry for the conflicts I caused. When rebasing please make sure that there are no COPY or other instructions changing permissions after the chown/chmod combo. Feel free to ping me if you're unsure.

[dervoeti]

@lfrancke @siegfriedweber I rebased my changes on top of the current main branch now