Handling of build variants, target platforms, platform-specific dependencies, etc.

[sschuberth]

In the very early days, ORT (and specifically the analyzer) was designed to be run locally, in the same environment as used for building a project. This ensured that the correct dependencies for the specific target platform were determined. However, by now it's common practice to run a central ORT instance in some sort of (CI / CD) pipeline (ORT "as a service"). As those pipelines mostly run on Linux, also only Linux-specific dependencies are determined by the analyzer.

So we have the general problem of varying dependencies depending on the target platform due to platform-specific dependencies.

More causes for varying dependencies can be the general topic of "build variants", e.g. Maven profiles, or optional dependencies that are e.g. only required for a specific (older) Python version, but not for another (newer) one.

This issue tries to bundle all related issues in an epic to discuss individual solutions, see the list below:

• Take only specified Maven profiles into account instead of the default one #1774
• Generally support platform specific dependencies #4013
• Android: Analyzer fails because Gradle cannot choose between multiple project variants #4694