Release 4.0.4

[Garandor]

Description

This release activates 4M KMA self-bond limit for all collators.

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• Connected to an issue with discussion and accepted design using zenhub "Connect issue" button below
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• Added one or more labels from the A- and C- groups to this PR
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Situational Notes:

• If adding functionality, write unit tests!
• If importing a new pallet, choose a proper module index for it, and allow it in BaseFilter. Ensure every extrinsic works from front-end. If there's corresponding tool, ensure both work for each other.
• If needed, update our Javascript/Typescript APIs. These APIs are officially used by exchanges or community developers.
• If modifying existing runtime storage items, make sure to implement storage migrations for the runtime and test them with try-runtime. This includes migrations inherited from upstream changes, and you can search the diffs for modifications of #[pallet::storage] items to check for any.

[Dengjianping]

And I think this version should be bumped as well.
https://github.com/Manta-Network/Manta/blob/release-v4.0.4/.github/workflows/metadata_diff.yml#L7

[Garandor]

And I think this version should be bumped as well

Done and changed the release.md to catch these in the future. thx for pointing them out