Filter proxy IRRs when checking interrupt requests from the host

[cperezvargas]

Here are more details on where to filter proxy IRRs for TDX:

impl UhProcessor<'_, TdxBacked> {
fn try_poll_apic(&mut self, scan_irr: bool) -> Result<bool, UhRunVpError> {
if let Some(irr) = self.runner.proxy_irr() {
// TODO TDX: filter proxy IRRs.
if self.backing.lapic.can_offload_irr() {

[cperezvargas]

closing as this is a dup of #563