Remove clashes with legacy version when linking extension

[SamuelBilek]

Fixes #209. This would occur when an addon containing both bl_info and blender_manifest was linked while using Blender < 4.2 and later using Blender 4.2+. Then there would be two installations of the same addon (one legacy and one extension) loaded into Blender 4.2+ which is undesirable.

[Mateusz-Grzelinski]

Please note that this can also happen when using only 4.2 for example when your are migrating from add-on to extension. But yes, you described typical situation.

Do you think the reverse situation can happen? Meaning you first use add-on as extension and then as add-on? Can you handle that situation too?

[SamuelBilek]

Using 4.2 and then a lower version also creates duplicate links, however, they do not cause any conflicts, as lower Blender versions do not have notion of extension. The current API for cleaning links in this extension doesn't really allow to clean extension links while using lower version than 4.2, as it heavily relies on the Blender extensions API. However, once the user decides to use 4.2+ again the duplicate links get removed.

[Mateusz-Grzelinski]

Hmm, od user tries really hard I think you can break it in the way I mentioned... But let's leave it for now.

Anyways, this is a step in good direction, I will merge when I get home.

Thank you for contribution!

I encourage to take a look at open PRs 😉

[SamuelBilek]

@Mateusz-Grzelinski @JacquesLucke Any estimation when a new version will be released? Our team would really like to have this change :)

[JacquesLucke]

I can do a release later this week.