kepler: getKernelVersion doesn't work at all

Describe the bug A clear and concise description of what the bug is.

https://github.com/sustainable-computing-io/kepler/blob/main/pkg/config/config.go#L65

paste those to https://go.dev/play/ and run it

package main

import (
	"encoding/json"
	"fmt"

	"github.com/zcalusic/sysinfo"
)

func main() {

	var si sysinfo.SysInfo

	si.GetSysInfo()

	data, err := json.MarshalIndent(&si, "", "  ")
	if err == nil {
		var result map[string]map[string]string
		if err = json.Unmarshal(data, &result); err != nil {
			fmt.Println("----")
			fmt.Println(err)
			fmt.Println("----")
		}
	}
	fmt.Println("done")
}

----
json: cannot unmarshal number into Go value of type string
----
done

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Expected behavior A clear and concise description of what you expected to happen.

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Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context Add any other context about the problem here.