cvar floats should use invariant culture

Runtime/Engine/Code/Foundation/ConfigVar.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Globalization;
 
 namespace RebootKit.Engine.Foundation {
     public enum CVarValueKind {
@@ -44,7 +45,7 @@ namespace RebootKit.Engine.Foundation {
 
         public override string ToString() {
             return kind switch {
-                CVarValueKind.Number => numberValue.ToString(),
+                CVarValueKind.Number => numberValue.ToString(CultureInfo.InvariantCulture),
                 CVarValueKind.String => $"{stringValue}",
                 _ => throw new ArgumentOutOfRangeException()
             };
@@ -151,7 +152,7 @@ namespace RebootKit.Engine.Foundation {
                 return;
             }
 
-            if (float.TryParse(str, out float f)) {
+            if (float.TryParse(str, NumberStyles.Float, CultureInfo.InvariantCulture, out float f)) {
                 Set(f);
             } else {
                 Set(str);