PHP 8.2 notes that utf8_encode() and utf8_decode() are deprecated because they can introduce obscure bugs. More info here.
Use of the functions are found in branch 7.x-2.x and below. 8.x and 3.x don't use these functions.
The functions convert strings between ISO-8859-1 (Also known as "Latin 1") and UTF-8 encodings. These functions do not attempt to detect the actual character encoding in a given text, and always convert character encodings between ISO-8859-1 and UTF-8, even if the source text is not encoded in ISO-8859-1.
So instead of assuming ISO-8859-1, it seems like the best approach is to first detect the encoding then to convert it.
Example:
mb_convert_encoding($item, "UTF-8", mb_detect_encoding($item));
Patch coming in a followup comment.
Needs review
2.0
Code
Attached patch uses the proposed resolution.
Fix for accidental overwriting of string in last patch.