Add support for PostgreSQL 17 and update related test configurations

Signed-off-by: Lucifergene <47265560+Lucifergene@users.noreply.github.com>

docs/backend-system/building-plugins-and-modules/02-testing.md

@@ -190,7 +190,7 @@ describe('MyDatabaseClass', () => {
   // "physical" databases to test against is much costlier than creating the
   // "logical" databases within them that the individual tests use.
   const databases = TestDatabases.create({
-    ids: ['POSTGRES_16', 'POSTGRES_12', 'SQLITE_3', 'MYSQL_8'],
+    ids: ['POSTGRES_17', 'POSTGRES_13', 'SQLITE_3', 'MYSQL_8'],
   });
 
   // Just an example of how to conveniently bundle up the setup code
@@ -236,8 +236,8 @@ your CI environment is able to supply databases natively, the `TestDatabases`
 support custom connection strings through the use of environment variables that
 it'll take into account when present.
 
+- `BACKSTAGE_TEST_DATABASE_POSTGRES17_CONNECTION_STRING`
 - `BACKSTAGE_TEST_DATABASE_POSTGRES13_CONNECTION_STRING`
-- `BACKSTAGE_TEST_DATABASE_POSTGRES9_CONNECTION_STRING`
 - `BACKSTAGE_TEST_DATABASE_MYSQL8_CONNECTION_STRING`
 
 ## Testing Service Factories