repo: Release v1.35.12

**Summary of changes**:

* Bug fixes:
  - runtime: fixed RTDS runtime guard override removal so deleting an override restores the process-wide runtime guard value to the default value.

* New features:
  - http2: added opt-in histograms for HTTP/2 header statistics, including header-entry count, header-map byte size, reassembled ``cookie`` header length, and individual ``cookie`` header count. Enable with ``envoy.reloadable_features.http2_record_histograms``; the histograms and runtime guard will be removed in a future Envoy release.
  - http2: added ``envoy.reloadable_features.http2_max_cookies_size_in_kb`` to limit the size of the reassembled ``cookie`` header. By default, no cookie-size limit is enforced.

**Docker images**:
    https://hub.docker.com/r/envoyproxy/envoy/tags?page=1&name=v1.35.12
**Docs**:
    https://www.envoyproxy.io/docs/envoy/v1.35.12/
**Release notes**:
    https://www.envoyproxy.io/docs/envoy/v1.35.12/version_history/v1.35/v1.35.12
**Full changelog**:
    v1.35.11...v1.35.12

Author: publish-envoy[bot]

VERSION.txt

@@ -1 +1 @@
-1.35.12-dev
+1.35.12

docs/inventories/v1.35/objects.inv

@@ -28,4 +28,4 @@
 "1.32": 1.32.13
 "1.33": 1.33.14
 "1.34": 1.34.14
-"1.35": 1.35.10
+"1.35": 1.35.11