fix: normalize return type and add PHPStan suppression for intentional type violation test

Author: gr8man

system/Session/Handlers/Database/PostgreHandler.php

@@ -59,7 +59,7 @@ protected function prepareData(string $data): string
      * @param int $max_lifetime Sessions that have not updated
      *                          for the last max_lifetime seconds will be removed.
      */
-    public function gc(int $max_lifetime): int|false
+    public function gc(int $max_lifetime): false|int
     {
         $separator = '\'';
         $interval  = implode($separator, ['', "{$max_lifetime} second", '']);

system/Session/Handlers/DatabaseHandler.php

@@ -276,7 +276,7 @@ public function destroy($id): bool
      *
      * @return false|int Returns the number of deleted sessions on success, or false on failure.
      */
-    public function gc(int $max_lifetime): int|false
+    public function gc(int $max_lifetime): false|int
     {
         return $this->db->table($this->table)->where(
             'timestamp <',

tests/system/Session/Handlers/Database/AbstractHandlerTestCase.php

@@ -19,6 +19,7 @@
 use CodeIgniter\Test\ReflectionHelper;
 use Config\Database as DatabaseConfig;
 use Tests\Support\Database\Seeds\CITestSeeder;
+use TypeError;
 
 /**
  * @internal
@@ -127,8 +128,8 @@ public function testGCRejectsNonInt(): void
     {
         $handler = $this->getInstance();
 
-        $this->expectException(\TypeError::class);
-        $handler->gc('malicious; DROP TABLE sessions; --');
+        $this->expectException(TypeError::class);
+        $handler->gc('malicious; DROP TABLE sessions; --'); // @phpstan-ignore argument.type
     }
 
     public function testGCWithZero(): void