Fails to build with TimescaleDB 2.9.0

[syvb]

#664 fails to build because of what seems to be an issue with TimescaleDB:

The CI for that PR fails on PG15 and also PG13 because the database system is in recovery mode:

running 15 test files
Starting stateless tests
Starting docs/asap.md
Starting docs/stats_agg.md
Finished docs/asap.md
error dropping DB connection closed
Starting docs/client.md
Finished docs/stats_agg.md
thread '<unnamed>' panicked at 'could not connect to postgres: Error { kind: Db, cause: Some(DbError { severity: "FATAL", parsed_severity: Some(Fatal), code: SqlState(E57P03), message: "the database system is in recovery mode", detail: None, hint: None, position: None, where_: None, schema: None, table: None, column: None, datatype: None, constraint: None, file: Some("postmaster.c"), line: Some(2403), routine: Some("ProcessStartupPacket") }) }', tools/sql-doctester/src/runner.rs:79:18

I got a similar failure the first time I ran the doc-tests locally, the second and third times I got strange results (another run) where test results get slightly off (although sometimes the errors are larger) results. e.g.:

Delta
 1 |       0.00
 2 |       0.00
 3 |       0.00
 4 |       0.42
 5 | -1.61+1.44
 6 | -2.59+2.66
 7 | -2.90+3.00
 8 | -3.20+3.36
 9 | -4.47+4.43
10 | -4.42+4.89
11 | -5.84+5.94
12 | -4.97+4.98

[syvb]

The database crash was fixed by TimescaleDB 2.9.1. The test results changes turned out to be caused by an unrelated change to random in Postgres 15.