test: remove 2021 test projects except "HdrpStereoGraphicsTest-2021.3"

[sindharta]

No description provided.

[H3idi-X]

Is it really OK to remove 2021.3? It looks we still support 2021.3 for Enterprise Customers.
https://unity.com/ja/blog/unity-2021-long-term-support-extended

[sindharta]

Yes. A couple of reasons:

1. Enterprise Customers will receive support for 2021.3 until May 2025. That's only one month left
2. Unity Toon Shader is experimental, and thus does not qualify as one of the supported packages (strictly speaking)
3. I am in the middle of removing duplicate files after putting our samples as symbolic links into our test projects (PR). Removing 2021 projects will reduce the amount of effort to accomplish this.

[H3idi-X]

Let me clarify.

It looks Enterprise customres can get support until May 30, 2026, not May 30, 2025. because the following says they will get an additional year of support.

Unity 2022 LTS. No change. Fully supported until at least May 30, 2025. Enterprise customers will receive an additional year of support.

https://unity.com/blog/unity-2021-long-term-support-extended

Unity 2022 LTS変更はありません。少なくとも 2025 年 5 月 30 日までは完全なサポートが提供されます。Unity Enterprise、または Unity Industry をご利用のお客様には、さらに 1 年間サポートが追加されます。

https://unity.com/ja/blog/unity-2021-long-term-support-extended

[sindharta]

We are talking about Unity 2021, right ?
Not Unity 2022 ?

[H3idi-X]

Oh, sorry for my misunderstanding.

[karasusan]

We have the HDRP-DefaultVolumeProject-2020.3 in the repo.
Should we remove the folder in another PR?

[sindharta]

HDRP-DefaultVolumeProject-2020.3 is not a CI test project, so yes, if we decide to remove it, we can remove it in a different PR.