Concurrency warning when conforming `ChartViewDelegate` with MainActor attribute.

* [v] I've read, understood, and done my best to follow the [*CONTRIBUTING guidelines](https://github.com/jjatie/Charts/blob/master/CONTRIBUTING.md).

## What did you do?

In Xcode 15, I conformed `ChartViewDelegate` to assign it to `LineChartView`.

## What did you expect to happen?

LineChartView works fine with no warning.

## What happened instead?

The following warning is displayed on the implemented functions.
```
Main actor-isolated instance method 'chartValueSelected(_:entry:highlight:)' cannot be used to satisfy nonisolated protocol requirement
```

## DGCharts Environment

**DGCharts version/Branch/Commit Number:** v5.1.0
**Xcode version:** 15.4
**Swift version:** 5.9
**Platform(s) running DGCharts:** iOS 17.5 Simulator
**macOS version running Xcode:** macOS Sonoma 14.5

## Demo Project

[ChartsWithMainActor.zip](https://github.com/user-attachments/files/15956210/ChartsWithMainActor.zip)