proxy: v2.221.0

---

* build(deps): bump rcgen from 0.11.3 to 0.12.0 (linkerd/linkerd2-proxy#2677)
* build(deps): bump jobserver from 0.1.26 to 0.1.27 (linkerd/linkerd2-proxy#2679)
* build(deps): bump bumpalo from 3.12.0 to 3.14.0 (linkerd/linkerd2-proxy#2678)
* outbound: Log and remove l5d-proxy-error from responses (linkerd/linkerd2-proxy#2694)
* http: Parameterize NewServeHttp (linkerd/linkerd2-proxy#2696)
* gateway: Avoid double http prefixing in metric names (linkerd/linkerd2-proxy#2701)

Signed-off-by: Oliver Gould <ver@buoyant.io>

.proxy-version

@@ -1 +1 @@
-v2.220.0
+v2.221.0