scripts/ingest_perf_test_result.py: increase connection timeout (#4329)

## Problem

Sometimes default connection timeout is not enough to connect to the DB
with perf test results, [an
example](https://github.com/neondatabase/neon/actions/runs/5064263522/jobs/9091692868#step:10:332).

Similar changes were made for similar scripts:
- For `scripts/flaky_tests.py` in
#4096
- For `scripts/ingest_regress_test_result.py` in
#2367 (from the very
begginning)

## Summary of changes
- Connection timeout increased to 30s for
`scripts/ingest_perf_test_result.py`

scripts/ingest_perf_test_result.py

@@ -35,7 +35,7 @@ def get_connection_cursor():
     connstr = os.getenv("DATABASE_URL")
     if not connstr:
         err("DATABASE_URL environment variable is not set")
-    with psycopg2.connect(connstr) as conn:
+    with psycopg2.connect(connstr, connect_timeout=30) as conn:
         with conn.cursor() as cur:
             yield cur