refactor: move from io/ioutil to io and os packages

The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

v2/internal/system/operatingsystem/os_linux.go

@@ -5,7 +5,6 @@ package operatingsystem
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"strings"
 )
@@ -17,7 +16,7 @@ func platformInfo() (*OS, error) {
 		return nil, fmt.Errorf("unable to read system information")
 	}
 
-	osRelease, _ := ioutil.ReadFile("/etc/os-release")
+	osRelease, _ := os.ReadFile("/etc/os-release")
 	return parseOsRelease(string(osRelease)), nil
 }