CPU Frequency chart maximum too restrictive

### What Happened?

The current maximum for the cpu frequency graph is at 5GHz.

Looking at the top gaming cards from AMD, this falls short:

https://www.amd.com/en/products/processors/desktops/ryzen.html#enthusiast

This also is the case for intel:

https://www.intel.com/content/www/us/en/products/details/processors/core.html

A fix could be to upon starting the app, find the maximum frequency of a cpu and add an arbitrary value to it, e.g. + 1,000.

A workaround for this locally can be to adjust the value at line 57 in `src/Views/SystemView/SystemCPUInfoPopover.vala` from `5.0` to `X.0`

### Steps to Reproduce

1. Have a high CPU clock rate and have it show up in the app
> This can be achieved in a few different ways: update the freq to show the max value, use frequency lock (some vendors support that), or you can average the freq across used cores (which is what I have running now).

### Expected Behavior

The graph to be fully visible to higher-end cpus that are overclocked (or have auto-configured like mine does), or perhaps to be a bit more dynamic, closer to what user runs for the max.

### OS Version

Other Linux

### OS Architecture

amd64 (on most hardwares)

### Session Type

Secure Session (Wayland)

### Software Version

Compiled from git

### Log Output

```shell

```

### Hardware Info

AMD 9950x overclocked, so the range typically is above the max.