feat(core): Make postgres pool-size configurable (no-changelog) (#7772)

When we upgrade typeorm in #5151, we switched from no pooling to a
default pool-size of 10. This somehow significantly deteriorates the
performance of queries when the application is under load.

packages/cli/src/databases/config.ts

@@ -61,6 +61,7 @@ export const getPostgresConnectionOptions = (): PostgresConnectionOptions => ({
 	type: 'postgres',
 	...getDBConnectionOptions('postgresdb'),
 	schema: config.getEnv('database.postgresdb.schema'),
+	poolSize: config.getEnv('database.postgresdb.poolSize'),
 	migrations: postgresMigrations,
 });