Remove code in preparation for v5.0 (#4258)

Co-authored-by: Ernesto García <ernestognw@gmail.com>
Co-authored-by: Francisco <fg@frang.io>

contracts/interfaces/IERC777Recipient.sol

@@ -1,6 +1,34 @@
 // SPDX-License-Identifier: MIT
-// OpenZeppelin Contracts v4.4.1 (interfaces/IERC777Recipient.sol)
 
 pragma solidity ^0.8.0;
 
-import "../token/ERC777/IERC777Recipient.sol";
+/**
+ * @dev Interface of the ERC777TokensRecipient standard as defined in the EIP.
+ *
+ * Accounts can be notified of {IERC777} tokens being sent to them by having a
+ * contract implement this interface (contract holders can be their own
+ * implementer) and registering it on the
+ * https://eips.ethereum.org/EIPS/eip-1820[ERC1820 global registry].
+ *
+ * See {IERC1820Registry} and {IERC1820Implementer}.
+ */
+interface IERC777Recipient {
+    /**
+     * @dev Called by an {IERC777} token contract whenever tokens are being
+     * moved or created into a registered account (`to`). The type of operation
+     * is conveyed by `from` being the zero address or not.
+     *
+     * This call occurs _after_ the token contract's state is updated, so
+     * {IERC777-balanceOf}, etc., can be used to query the post-operation state.
+     *
+     * This function may revert to prevent the operation from being executed.
+     */
+    function tokensReceived(
+        address operator,
+        address from,
+        address to,
+        uint256 amount,
+        bytes calldata userData,
+        bytes calldata operatorData
+    ) external;
+}