proxy: v2.212.0 (#11557)

This release includes several bugfixes. Notably, inbound proxies would
not properly reflect grpc-status in metrics by default.

Furthermore, proxies now long warnings when they receive unexpected
error responses from the control plane.

---

* chore: change `rust-toolchain` file to toml format (linkerd/linkerd2-proxy#2487)
* gate: Detect disconnected inner services in readiness (linkerd/linkerd2-proxy#2491)
* Bump ahash to v0.8.5 (linkerd/linkerd2-proxy#2498)
* gate: Fix readiness deadlock (linkerd/linkerd2-proxy#2493)
* Log a warning when the controller clients receive an error (linkerd/linkerd2-proxy#2499)
* inbound: Fix gRPC response classification (linkerd/linkerd2-proxy#2496)

Signed-off-by: Oliver Gould <[email protected]>

.proxy-version

@@ -1 +1 @@
-v2.211.0
+v2.212.0