How to modify MySQL/MariaDB .sql export file not breaking character/set?

Hello, please how to properly modify MySQL database export file .sql so the character set is not changed/content is not broken after saving/importing the modified file?

I have opened the file in Linux editor Kate and saved a modified copy of the file with default UTF-8 charset, then uploaded the file to the new database using PHPMyAdmin (while left selected default utf-8 charset of the file) or using BigDump php script. In both cases the charset was likely wrong, since CMS errored, saying that I was likely "importing your database tables using the wrong character set or collation". Importing original/unmodified .sql file (using BidDump which had "$db_connection_charset = 'utf8';" set as in previous case where i have imported a modified .sql file) made the site working. So the problem is likely in a wrong charset used in saving the file or less likely I did some error in editing the file?

Original .sql export file header:

/*M!999999- enable the sandbox mode */
– MariaDB dump 10.19 Distrib 10.6.20-MariaDB, for Linux (x86_64)

– Host: localhost Database: ***
– Server version 10.6.20-MariaDB-cll-lve

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT /;
/!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS /;
/!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION /;
/!40101 SET NAMES utf8mb4 /;
/!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE /;
/!40103 SET TIME_ZONE=‘+00:00’ /;
/!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 /;
/!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 /;
/!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE=‘NO_AUTO_VALUE_ON_ZERO’ /;
/!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

Code (markup):

Source DB and imported DBs shows collation latin1_swedish_ci, type MyISAM. Both DBs are on same physical server with 10.6.20-MariaDB-cll-lve, Server charset: cp1252 West European (latin1), Server connection collation: utf8mb4_unicode_ci

My question is how to modify and save the copy of the file properly in this case, please?

 

You'd be better off asking this on stackoverflow or reddit.