Vendor wgpu-hal 29.0.4 and i-slint-renderer-skia 1.17.1, unmodified

The Android develop view reads its frame back through memory (TD-1)
because wgpu's Vulkan swapchain never pre-rotates, and a portrait window
on this tablet's landscape panel then tears. The fix is a small patch to
each of these two crates, and this commit is only the ground it lands on:
both are byte-for-byte the crates.io sources the lockfile already
resolved, so the commits that follow are the patch and nothing else.

third_party/ is excluded from the workspace, or every path dependency
under the root would become a member and `--workspace` would test and
lint upstream code as ours. The README says how to carry the patches
across a Slint or wgpu bump, which matters because a stale version here
does not fail the build — cargo just warns and uses the unpatched crate.

third_party/wgpu-hal-29.0.4/src/validation_canary.rs

@@ -0,0 +1,39 @@
+use alloc::{string::String, vec::Vec};
+
+use parking_lot::Mutex;
+
+/// Stores the text of any validation errors that have occurred since
+/// the last call to `get_and_reset`.
+///
+/// Each value is a validation error and a message associated with it,
+/// or `None` if the error has no message from the api.
+///
+/// This is used for internal wgpu testing only and _must not_ be used
+/// as a way to check for errors.
+///
+/// This works as a static because `cargo nextest` runs all of our
+/// tests in separate processes, so each test gets its own canary.
+///
+/// This prevents the issue of one validation error terminating the
+/// entire process.
+pub static VALIDATION_CANARY: ValidationCanary = ValidationCanary {
+    inner: Mutex::new(Vec::new()),
+};
+
+/// Flag for internal testing.
+pub struct ValidationCanary {
+    inner: Mutex<Vec<String>>,
+}
+
+impl ValidationCanary {
+    #[allow(dead_code)] // in some configurations this function is dead
+    pub(crate) fn add(&self, msg: String) {
+        self.inner.lock().push(msg);
+    }
+
+    /// Returns any API validation errors that have occurred in this process
+    /// since the last call to this function.
+    pub fn get_and_reset(&self) -> Vec<String> {
+        self.inner.lock().drain(..).collect()
+    }
+}