SAST analyzer error with .NET - Unable to build project using `dotnet`

Summary

So I have exactly the same problem as #300368 (closed) already described:
Using the SAST CI template with a .NET project produces "Unable to build project using dotnet".

Steps to reproduce

New Repo
Create dotnet project
Create CI/CD job:

stages:
- test
sast:
  stage: test
include:
- template: Security/SAST.gitlab-ci.yml

Job fails.

Example Project

Project with two jobs: build, which successfully executes dotnet build, and the included SAST job.
Link goes directly to the failing job:

https://gitlab.com/Regenhardt/custom-vision-lib/-/jobs/1943170953

What is the current bug behavior?

Job fails, producing "Unable to build project using dotnet"

What is the expected correct behavior?

Job should analyse the project.

Relevant logs and/or screenshots

Output of checks

This bug happens on GitLab.com

Possible fixes

Tried adding a before_script to the SAST job installing dotnet-sdk-6.0 as mentioned as a workaround in the previous issue, but it just fails since neither apt nor apt-get can be found.