There is no official way, but you can hack the property grid, accessing it's internal controls.

Here is a sample code that tries to do it the most gracefully possible. You could also test if the last control's text is "Property Pages", but it may not work with localized versions.

var buttons = propertyGrid1.Controls.OfType<ToolStrip>().FirstOrDefault()?.Items;
if (buttons != null &&
    buttons.Count >= 2 &&
    buttons[buttons.Count - 1] is ToolStripButton && // could test Text...
    buttons[buttons.Count - 2] is ToolStripSeparator)
{
    buttons[buttons.Count - 1].Visible = false;
    buttons[buttons.Count - 2].Visible = false;
}

Use at your own risks.