databases/py-mysqlclient: update to 1.4.6 release

• The cp1252 encoding is used when charset is "latin1". (#390)
• The auth_plugin option is added. (#389)
• charset option is passed to mysql_options(mysql, MYSQL_SET_CHARSET_NAME, charset) before mysql_real_connect is called. This avoid extra SET NAMES <charset> query when creating connection.
• --static build supports libmariadbclient.a
• Try mariadb_config when mysql_config is not found
• Fixed warning happend in Python 3.8 (#359)
• Fixed SEGV MySQLdb.escape_string("1") when libmariadb is used and no connection is created. (#367)
• Fixed many circular references are created in Cursor.executemany(). (#375)

PR: 243076
Submitted by: fluffy
Approved by: maintainer timeout (>1w)