Fix odbc_data_source_001.phpt

As of PHP 8.1.0, passing `null` to an `int` parameter is deprecated,
and as such the deprecation notice breaks the test.  So we instead pass
an integer, and to avoid hard-coding a value we just add the two
supported constants (which are supposed to have the values `1` and `2`,
respectively).

Closes GH-15254.

Author: cmb69

ext/odbc/tests/odbc_data_source_001.phpt

@@ -17,7 +17,7 @@ include 'config.inc';
 $conn = odbc_connect($dsn, $user, $pass);
 
 try {
-    var_dump(odbc_data_source($conn, NULL));
+    var_dump(odbc_data_source($conn, SQL_FETCH_FIRST + SQL_FETCH_NEXT));
 } catch (\ValueError $e) {
     echo $e->getMessage() . \PHP_EOL;
 }