call to undefined function mysql_connect

Trying to run a search and replace but am getting an error

 Call to undefined function mysql_connect() in E:\xampp\htdocs\test\wp-includes\wp-db.php:1688

I have checked my WP files and have both mysqli_connect and msql_connect referenced in there. I have tried to replace all mysql_connect references to mysqli_connect however I then get the same error for the new name

 Call to undefined function mysqli_connect() in E:\xampp\htdocs\test\wp-includes\wp-db.php:1688

When I run wp --info I get:

OS:     Windows NT 10.0 build 18363 (Windows 10) AMD64
Shell:  C:\Windows\system32\cmd.exe
PHP binary:     C:\PHP7\php.exe
PHP version:    7.4.9
php.ini used:   C:\PHP7\php.ini
WP-CLI root dir:        phar://wp-cli.phar/vendor/wp-cli/wp-cli
WP-CLI vendor dir:      phar://wp-cli.phar/vendor
WP_CLI phar path:       E:\xampp\htdocs\test
WP-CLI packages dir:
WP-CLI global config:
WP-CLI project config:
WP-CLI version: 2.4.0