Missing duplicate token validation in `setTargetWeight`

The setTargetWeight function lacks validation for duplicate tokens in the input array, which could lead to inconsistent weight assignments. Here's the problematic code:

function setTargetWeight(TokenWeight[] calldata tokens)
    external
    onlyRole(AccessControlStorage.DEFAULT_ADMIN_ROLE)
{
    PoolStorage.AssetsConfig storage assets = PoolStorage.layout().setUp.assets;
    uint256 nTokens = tokens.length;
    if (nTokens != assets.allAssets.length()) revert PoolErrors.RequireAllTokens();

    uint256 total;
    TokenWeight memory item;
    uint256 weight;
    for (uint8 i; i < nTokens;) {
        item = tokens[i];
        assert(assets.allAssets.contains(item.token));
        weight = assets.isListed[item.token] ? item.weight : 0;
        assets.targetWeights[item.token] = weight;
        total += weight;
        // ... increment i
    }
    assets.totalWeight = total;
}

The issue arises because:

1. The function only checks if the number of tokens matches assets.allAssets.length().
2. There is no validation to ensure each token appears exactly once in the input array.
3. If a token appears multiple times in the input array:
   • Each occurrence will overwrite the previous weight assignment.
   • Only the last occurrence's weight will be stored.
   • The totalWeight calculation will include all occurrences.

To mitigate this issue, it is recommended to add validation to ensure each token appears exactly once(by checking address ordering).