Document platforms supported

[baentsch]

Implement result of discussion.

[baentsch]

Suggest disabling Windows2019 CI as that is also not tested in liboqs. @dstebila : What level of Windows (CI) support do we want to attain? fwiw, latest CI problems in oqsprovider were triggered by a failed liboqs Windows2019 CI check (now disabled for oqsprovider0.5.3/liboqs0.9.2 RC).

[baentsch]

Contrary to the last comment and as per separate discussion suggest to align platforms supported by OpenSSL with those supported by oqsprovider to ease usage of both at the same time. Depends (mostly) on open-quantum-safe/liboqs#1691.

[baentsch]

Moving this issue forward also depends on the level of commitment by the community. Yours truly does not have the bandwidth to provide support for more than basic Ubuntu support. Hence, documenting more platforms as properly supported would be misleading. Same issue as with #94.

[baentsch]

@dstebila OK to close this issue? Your demand in yesterday's meeting to spend more cycles on a platform we documented as not CI-supported (IMO effectively disregarding/valuing as irrelevant the PLATFORMS.md file of liboqs) leads me to wonder why we should document the same here knowing it's getting ignored if it can/would be used to guide decisions as to what to focus on?

[dstebila]

I was caught off guard yesterday and didn't realize that Ubuntu x86 was not in our PLATFORMS.md file. Obviously we had x86_64 Ubuntu, and we had x86 Zephyr and x86 Windows, so I was surprised that x86 Ubuntu wasn't in there. However unless anyone speaks up (with a willingness to contribute) I don't think there's a need to revisit and I'm okay with letting it go as per our PLATFORMS.md file. @SWilson4 any thoughts?

[SWilson4]

I'll explicitly mention in the (upcoming) PR that CI support for x86 is being removed. If anyone has an objection, they'll have a chance to raise it during the review process, and we can iterate on the PLATFORMS file as necessary.