proxy: v2.171.0

This release adds a new configuration variable,
`LINKERD2_PROXY_ACCESS_LOG` that configures whether per-request access
logs are emitted from inbound HTTP proxies. This variable may be set to
`apache` for Apache Common Log output or `json` for JSON formatted logs.
Access logs are emitted to stderr and the proxy's diagnostics logs are
emitted to stdout.

---

* build(deps): bump h2 from 0.3.9 to 0.3.10 (linkerd/linkerd2-proxy#1430)
* Update Rust to v1.56.1 (linkerd/linkerd2-proxy#1431)
* build(deps): bump indexmap from 1.7.0 to 1.8.0 (linkerd/linkerd2-proxy#1433)
* Add a devcontainer config (linkerd/linkerd2-proxy#1432)
* build(deps): bump serde_json from 1.0.74 to 1.0.75 (linkerd/linkerd2-proxy#1436)
* build(deps): bump tracing-subscriber from 0.3.5 to 0.3.6 (linkerd/linkerd2-proxy#1435)
* test: remove `env::set_var` call in test logging initialization  (linkerd/linkerd2-proxy#1437)
* trace: Apache Common Log Format access logging (linkerd/linkerd2-proxy#1319)
* build(deps): bump libc from 0.2.112 to 0.2.113 (linkerd/linkerd2-proxy#1438)
* build(deps): bump socket2 from 0.4.2 to 0.4.3 (linkerd/linkerd2-proxy#1439)
* access-log: Add JSON support (linkerd/linkerd2-proxy#1350)

.proxy-version

@@ -1 +1 @@
-v2.170.0
+v2.171.0