consolidate test dirs and remove unused block library

Author: willemolding

contracts/foundry.toml

@@ -2,7 +2,7 @@
 src = "src"
 out = "out"
 libs = ["lib", "dependencies"]
-test = "test"
+test = "tests"
 ffi = true
 fs_permissions = [{ access = "read-write", path = "./"}]
 remappings = [

contracts/src/BlockRoots.sol

@@ -19,7 +19,6 @@ pragma solidity ^0.8.20;
 import {IRiscZeroVerifier} from "risc0/IRiscZeroVerifier.sol";
 import {Steel} from "risc0/steel/Steel.sol";
 import {ISecondOpinionOracle} from "./ISecondOpinionOracle.sol";
-import {BlockRoots} from "./BlockRoots.sol";
 import {ImageID} from "./ImageID.sol"; // auto-generated contract after running `cargo build`.
 import {Report, IOracleProofReceiver} from "./IOracleProofReceiver.sol";