Remove the evidence module in v4

[ninabarbakadze]

Description

After writing AppHash test we realised that we have a msg MsgSubmitEvidence that's not used and should probably be disabled in v3

[rootulp]

Can you elaborate on how/why it's not used? It looks like it's part of the x/evidence module still: https://github.com/celestiaorg/cosmos-sdk/blob/release/v0.46.x-celestia/x/evidence/spec/03_messages.md#msgsubmitevidence

[rootulp]

Additional context from in-person sync:

• Most Cosmos chains have this module but don't use it because evidence is handled by CometBFT.
• We've had x/evidence since app version 1 and it hasn't been an issue so far.
• Given this is a "nice to have" it likely won't be included in v3

[tac0turtle]

by removing evidence you allow validators to double sign with no repercussion: https://github.com/cosmos/cosmos-sdk/blob/fc91e76354512e8538f9da5bc9d3518f54921417/x/evidence/keeper/abci.go#L28. Is this desired?