The Neo4j official Go driver's session object has a ReadTransaction method that you can use for marking read queries explicitly.

For Version 4 of the driver, the below example using the ReadTransaction function is correct:

session := driver.NewSession(neo4j.SessionConfig{})
   defer session.Close()
    _, err = session.ReadTransaction(func(tx neo4j.Transaction) (interface{}, error) {
        getActorsRead := `
           MATCH (p:Person)-[:ACTED_IN]->(m)
           WHERE toLower(m.title) CONTAINS toLower($title)
           RETURN DISTINCT p.name as actorsTx`
        result, err := tx.Run(getActorsRead, map[string]interface{}{
            "title": "matrix",
       })
        if err != nil {
            return nil, err
       }
        for result.Next() {
            fmt.Printf("Found actor: '%s' \n", result.Record().Values[0].(string))
       }
        return nil, result.Err()
    })

For Version 5 of the driver, you need to use the ExecuteRead function instead:

session := driver.NewSession(neo4j.SessionConfig{})
   defer session.Close()
    _, err = session.ExecuteRead(func(tx neo4j.Transaction) (interface{}, error) {
        getActorsRead := `
           MATCH (p:Person)-[:ACTED_IN]->(m)
           WHERE toLower(m.title) CONTAINS toLower($title)
           RETURN DISTINCT p.name as actorsTx`
        result, err := tx.Run(getActorsRead, map[string]interface{}{
            "title": "matrix",
       })
        if err != nil {
            return nil, err
       }
        for result.Next() {
            fmt.Printf("Found actor: '%s' \n", result.Record().Values[0].(string))
       }
        return nil, result.Err()
    })