Delete legacy dev branches?

[clue]

We've recently renamed our master branches to reflect the current major version like 1.x / 2.x / 3.x / 4.x as discussed in reactphp/promise#212 and related tickets.

I've also checked all components and noticed we still have a number of legacy dev branches for deprecated versions laying around. These versions are no longer supported as per our LTS policy and haven't been updated in more than a few years. I'm not sure how much value these still provide, but I would argue that they can (and should) be deleted.

In particular, I would like to remove the following branches:

• reactphp/socket: 1.x stays. 0.3 and 0.4 should be removed.
• reactphp/event-loop: 1.x stays. 0.3 and 0.4 should be removed.
• reactphp/http: 1.x stays. 0.3, 0.4 and 0.5 should be removed.
• reactphp/reactphp: 1.x stays. 0.3 and 0.4 should be removed.
• reactphp/stream: 1.x stays. 0.3 and 0.4 should be removed.
• reactphp/cache: 1.x stays. 0.3 should be removed
• reactphp/child-process: 0.6.x and 0.7.x stay. 0.3 should be removed.

• ---

• reactphp/async: 2.x, 3.x and 4.x stay.
• reactphp/promise: 1.x, 2.x and 3.x stay.
• reactphp/datagram: 1.x stays.
• reactphp/dns: 1.x stays.
• reactphp/promise-timer: 1.x stays.
• reactphp/promise-stream: 1.x stays.

See this gist for all details: https://gist.github.com/clue/3f0382e8d86d8998fda7744d2d0a7995

This way, all projects would be aligned nicely. This would also be a nice preparation for future 3.x and/or 4.x branches as discussed in https://github.com/orgs/reactphp/discussions/472.

If there are no objections, I would like to go ahead with this in a week or two.

[clue]

I've just deleted as legacy branches as suggested. This has only a small chance of affecting anybody, as this should only affect legacy branches, but please report back if it does and we're happy to look into this.

Currently supported development branches will continue to work as is. Plus, we can now focus on upcoming v3 branches as per https://github.com/orgs/reactphp/discussions/481 🎉