Vendor dependencies

Let's see how I like this workflow.

vendor/thiserror/tests/ui/no-display.stderr

@@ -0,0 +1,17 @@
+error[E0599]: the method `as_display` exists for reference `&NoDisplay`, but its trait bounds were not satisfied
+ --> tests/ui/no-display.rs:7:9
+  |
+4 | struct NoDisplay;
+  | ---------------- doesn't satisfy `NoDisplay: std::fmt::Display`
+...
+7 | #[error("thread: {thread}")]
+  |         ^^^^^^^^^^^^^^^^^^ method cannot be called on `&NoDisplay` due to unsatisfied trait bounds
+  |
+  = note: the following trait bounds were not satisfied:
+          `NoDisplay: std::fmt::Display`
+          which is required by `&NoDisplay: DisplayAsDisplay`
+note: the trait `std::fmt::Display` must be implemented
+ --> $RUST/core/src/fmt/mod.rs
+  |
+  | pub trait Display {
+  | ^^^^^^^^^^^^^^^^^