virtio-devices: reevaluate #[allow] attributes

Convert the still-needed #[allow]s to #[expect] so they warn if the
lints stop firing.

Part of #8326.

Signed-off-by: Tushar Khatri <hello@tusharkhatri.in>

virtio-devices/src/vsock/device.rs

@@ -366,7 +366,7 @@ where
 {
     /// Create a new virtio-vsock device with the given VM CID and vsock
     /// backend.
-    #[allow(clippy::too_many_arguments)]
+    #[expect(clippy::too_many_arguments)]
     pub fn new(
         id: String,
         cid: u32,

virtio-devices/src/vsock/mod.rs

@@ -205,7 +205,7 @@ pub mod unit_tests {
         pub evset: Option<epoll::Events>,
     }
     impl TestBackend {
-        #[allow(clippy::new_without_default)]
+        #[expect(clippy::new_without_default)]
         pub fn new() -> Self {
             Self {
                 evfd: EventFd::new(EFD_NONBLOCK).unwrap(),
@@ -270,7 +270,7 @@ pub mod unit_tests {
     }
 
     impl TestContext {
-        #[allow(clippy::new_without_default)]
+        #[expect(clippy::new_without_default)]
         pub fn new() -> Self {
             const CID: u32 = 52;
             const MEM_SIZE: usize = 1024 * 1024 * 128;