new ingest benchmark (#9711)

## Problem

We have no specific benchmark testing project migration of postgresql
project with existing data into Neon.
Typical steps of such a project migration are
- schema creation in the neon project
- initial COPY of relations
- creation of indexes and constraints
- vacuum analyze

## Summary of changes

Add a periodic benchmark running 9 AM UTC every day.
In each run:
- copy a 200 GiB project that has realistic schema, data, tables,
indexes and constraints from another project into
  - a new Neon project (7 CU fixed)
- an existing tenant, (but new branch and new database) that already has
4 TiB of data
- use pgcopydb tool to automate all steps and parallelize COPY and index
creation
- parse pgcopydb output and report performance metrics in Neon
performance test database

## Logs

This benchmark has been tested first manually and then as part of
benchmarking.yml workflow, example run see

https://github.com/neondatabase/neon/actions/runs/11757679870

.github/actionlint.yml

@@ -20,3 +20,4 @@ config-variables:
   - REMOTE_STORAGE_AZURE_REGION
   - SLACK_UPCOMING_RELEASE_CHANNEL_ID
   - DEV_AWS_OIDC_ROLE_ARN
+  - BENCHMARK_INGEST_TARGET_PROJECTID