Obsolete dead sdks

[TheArcaneBrony]

Marked all SDKs under ecosystem with no new commits for over a year as obsolete.
Also fixes the git url for matrix.swift and qt version for quotient.
Please check commitlog (+description) since some commits may be dropped later as i'm awaiting maintainer respones (elm sdk @ 11 months, matrix.swift @ 9 months)

Also did not touch matrix-mellifluousness/sdk despite inactivity for 2 years, hmu if you'd like me to obsolete it for consistency.

Related issues: #1584
Contributing in a specific role: your link is broken btw :)
In any case, I had originally started checking C# SDKs, which I suppose may have a COI as I'm maintaining Rory&::LibMatrix

✔️ Checklist

• Check for common mistakes:
  • Wrap plain URLs in <> to linkify them (learn more).
  • Use the right level of headings: The page title will use a level 1 headings, so your headings should use level 2 and below.
  • Use internal links: when linking to another page on https://matrix.org, use the Zola [label](@/target.md) syntax.
• For blog posts:
  • Verify the date and post ordering on the /blog page, especially for multiple posts on the same day. Prefer UTC format, e.g. 2025-12-01T14:00:00Z for Dec 1st, 2025, 2pm UTC.
  • Set the correct author and category. Browse existing ones at https://matrix.org/author/ and https://matrix.org/category/ to match them.
• Let us know if you are contributing in a specific role, such as on behalf of an organisation or team, for example.
• Let us know if your PR is time-sensitive in any way.
• Mention any issues related to the PR. Use GitHub keywords as appropriate.
• Your individual commits or pull request is signed off.

[HarHarLinks]

Contributing in a specific role: your link is broken btw :)

Explain please? It is supposed to lead to #2788 which is a PR containing the notice "🎩 Website & Content WG". Admittedly we might update it to a PR that uses the complete current template.

may be dropped later as i'm awaiting maintainer respones

Should this be a draft PR then?

[TheArcaneBrony]

Should this be a draft PR then?

good point, i forgot those existed

It is supposed to lead to #2788 which is a PR containing the notice "🎩 Website & Content WG".

it didnt feel very intentional to link to a PR about a11y in images in context of COI notices?

[HarHarLinks]

It is supposed to lead to #2788 which is a PR containing the notice "🎩 Website & Content WG".

it didnt feel very intentional to link to a PR about a11y in images in context of COI notices?

CoI is one out of many concerns. Sometimes it's just context of why someone is doing something, or on whose authority. Would you be happier with #2969 as an example? -> moved to https://github.com/matrix-org/matrix.org/pull/2979/files#r2473508377