gh-100414: Skip test_dbm_sqlite3 if sqlite3 is unavailable (#115449)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
diff --git a/Lib/test/test_dbm_sqlite3.py b/Lib/test/test_dbm_sqlite3.py
index 7bc2a03..7a49fd2 100644
--- a/Lib/test/test_dbm_sqlite3.py
+++ b/Lib/test/test_dbm_sqlite3.py
@@ -1,4 +1,3 @@
-import sqlite3
 import sys
 import test.support
 import unittest
@@ -7,8 +6,12 @@
 from pathlib import Path
 from test.support import cpython_only, import_helper, os_helper
 
-
 dbm_sqlite3 = import_helper.import_module("dbm.sqlite3")
+# N.B. The test will fail on some platforms without sqlite3
+# if the sqlite3 import is above the import of dbm.sqlite3.
+# This is deliberate: if the import helper managed to import dbm.sqlite3,
+# we must inevitably be able to import sqlite3. Else, we have a problem.
+import sqlite3
 from dbm.sqlite3 import _normalize_uri