`sharedDecimals` function is defined as `pure` making it too restrictive

[Mattijah]

The sharedDecimals function is defined as pure, which makes overriding in a subclass impossible if the value returned is a locally defined constant (not pre-set in the contract with a literal). The tutorial or suggestion mentioning overriding of sharedDecimals using view is therefore also non-functional https://docs.layerzero.network/v2/developers/evm/oft/quickstart#token-supply-cap. The interface IOFTdefines the function with view as well, which should really be used:

LayerZero-v2/oapp/contracts/oft/interfaces/IOFT.sol

Line 104 in 142846c

function sharedDecimals() external view returns (uint8);