Add checks for scheduler being present #5

	# Test diagnostic script from timescaledb-extras works
	name: "Verify diagnostic script works"
	"on":
	schedule:
	# run daily 0:00 on main branch
	- cron: '0 0 * * *'
	pull_request:
	workflow_dispatch:
	jobs:
	diagnostic_test:
	name: Test diagnostic script PG${{ matrix.pg }}
	runs-on: ubuntu-latest
	services:
	ts:
	image: timescale/timescaledb:latest-pg${{ matrix.pg }}
	ports:
	- 5432:5432
	env:
	POSTGRES_HOST_AUTH_METHOD: trust
	POSTGRESQL_PASSWORD: ci

	env:
	PGHOST: localhost
	PGUSER: postgres
	PGPASSWORD: ci

	strategy:
	fail-fast: false
	matrix:
	pg: [15,16,17,18]

	steps:

	- uses: actions/checkout@v4

	- name: Wait for services to start
	run: \|
	sleep 10
	pg_isready -t 30

	- name: Prepare database
	run: \|
	psql -v ON_ERROR_STOP=1 -c "$(cat <<SQL
	SELECT version();
	SELECT extname, extversion from pg_extension;
	CREATE TABLE t(time timestamptz) WITH (tsdb.hypertable);
	INSERT INTO t SELECT '2025-01-01';
	INSERT INTO t SELECT '2025-02-01';
	SELECT compress_chunk(show_chunks('t'));
	SQL
	)"

	- name: Run diagnostic script
	run: \|
	psql -v ON_ERROR_STOP=1 < diagnostic.sql

Provide feedback