call transaction callbacks after updating the transaction levels (#36890)

Author: themsaid

src/Illuminate/Database/Concerns/ManagesTransactions.php

@@ -41,13 +41,13 @@ public function transaction(Closure $callback, $attempts = 1)
             }
 
             try {
-                if ($this->transactions == 1) {
+                $this->transactions = max(0, $this->transactions - 1);
+
+                if ($this->transactions == 0) {
                     $this->getPdo()->commit();
 
                     optional($this->transactionsManager)->commit($this->getName());
                 }
-
-                $this->transactions = max(0, $this->transactions - 1);
             } catch (Throwable $e) {
                 $this->handleCommitTransactionException(
                     $e, $currentAttempt, $attempts