chore: update README to include postgres17

Author: Kumzy

README.md

@@ -32,7 +32,7 @@ It is designed to offer pre-configured testing setups for many different types a
 
 `pytest-databases` currently utilizes `docker compose` (or the legacy `docker-compose`) commands to manage the startup and shutdown of each database service. The following databases are currently available:
 
-- **Postgres**: Version 12, 13, 14, 15, and 16 are available
+- **Postgres**: Version 12, 13, 14, 15, 16 and 17 are available
 - **MySQL**: Version 5.6, 5.7 and 8 are available
 - **Oracle**: Version 18c XE and 23C Free are available
 - **SQL Server**: Version 2022 is available