PSA: XCMv2 deprecation

Hello everyone! XCMv2 has been deprecated and it’s going to be removed when XCMv5 comes out.

If you’re using v2, it’s a good time to switch to the much better v3 or v4. The migration should be simple.

Please reply with any questions you might have about the migration and I’ll try my best to answer them :grin:.

We should collect XCM version info from onchain data and will have good idea of usage of each XCM version. It will also be useful for many other things. For example, we will know we can safely remove a particular XCM instruction if it has not been used for 3 months.