make these queries Postgres version specific

[github-actions]

get all schemas and table

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olake/drivers/postgres/internal/postgres.go

Lines 19 to 24 in ed705d2

	// TODO: make these queries Postgres version specific
	// get all schemas and table
	getPrivilegedTablesTmpl = `SELECT nspname as table_schema,
	relname as table_name
	FROM pg_class c
	JOIN pg_namespace n ON c.relnamespace = n.oid

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This issue was generated by todo-issue based on a TODO comment in ed705d2. It's been assigned to @hash-data because they committed the code.