Develop 1020

[wischli]

Description

• Adds missing migration (Remove duplicate metadata from pool-system #1285) to develop runtime
• Bumps spec version to 1020 required for the runtime upgrade execution

Fixes

• Pools not being decodable by runtime in 1019 spec version

How to test

This bump already successfully fixed the Dev chain.

Checklist:

• I have added Rust doc comments to structs, enums, traits and functions
• I have made corresponding changes to the documentation
• I have performed a self-review of my code
• I have added tests that prove my fix is effective or that my feature works

[wischli]

Closing as not relevant anymore

[lemunozm]

@wischli Why is this not relevant? Not sure if the reason to close this PR is that in #1314 I updated to UpgradeDev1020, but I missed changes for spec_version and Cargo.toml versions of development runtime.