No Story: Truncating ingest-envoy README.

Gitlab introduced a change last week limiting the length of metadata allowed for pypi packages to 4000 characters. The ingest-envoy package has roughly 4700 characters, causing all uploads to fail and breaking our pipeline; this (temporarily) reduces the character count to 3950 until Gitlab decides if they'll stick with this change or not. See the following link for my details on the issue: https://gitlab.com/gitlab-org/gitlab/-/issues/431505