Fix minor typo in IERC1155 and IERC721 docs (#3419)

contracts/token/ERC1155/IERC1155.sol

@@ -91,7 +91,7 @@ interface IERC1155 is IERC165 {
      * Requirements:
      *
      * - `to` cannot be the zero address.
-     * - If the caller is not `from`, it must be have been approved to spend ``from``'s tokens via {setApprovalForAll}.
+     * - If the caller is not `from`, it must have been approved to spend ``from``'s tokens via {setApprovalForAll}.
      * - `from` must have a balance of tokens of type `id` of at least `amount`.
      * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
      * acceptance magic value.

contracts/token/ERC721/IERC721.sol

@@ -67,7 +67,7 @@ interface IERC721 is IERC165 {
      * - `from` cannot be the zero address.
      * - `to` cannot be the zero address.
      * - `tokenId` token must exist and be owned by `from`.
-     * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
+     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
      * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
      *
      * Emits a {Transfer} event.