Test database locale, not server variables

In PostgreSQL 16, both `LC_COLLATE` and `LC_CTYPE` server variables have
been removed. This patch rewrites one test that checks their values in
order to make tests compatible with PostgreSQL 16, which is shipped with
Ubuntu 24.04 runners.

Reported-by: Yuri Astrakhan
Resolves: #38

Author: ikalnytskyi

test_action.py

@@ -101,11 +101,19 @@ def test_locale(connection: psycopg.Connection, is_windows_server_2019: bool):
     if is_windows_server_2019:
         locale_exp = "en-US"
 
-    lc_collate = connection.execute("SHOW LC_COLLATE").fetchone()[0]
-    lc_ctype = connection.execute("SHOW LC_CTYPE").fetchone()[0]
-
-    assert locale.normalize(lc_collate) == locale_exp
-    assert locale.normalize(lc_ctype) == locale_exp
+    record = connection \
+        .execute("SELECT datcollate, datctype FROM pg_database WHERE datname = 'template0'") \
+        .fetchone()
+    assert record
+    assert locale.normalize(record[0]) == locale_exp
+    assert locale.normalize(record[1]) == locale_exp
+
+    record = connection \
+        .execute("SELECT datcollate, datctype FROM pg_database WHERE datname = 'template1'") \
+        .fetchone()
+    assert record
+    assert locale.normalize(record[0]) == locale_exp
+    assert locale.normalize(record[1]) == locale_exp
 
 
 def test_environment_variables(is_windows: bool):