Fix missing scope on isShippingCarrierAvailable

The scope to isShippingCarrierAvailable is not applied from $request. This makes issues with shipping methods when quote is being created from backend via 3rd party modules.
This applies storeId scope directly from $request->getStoreId() to make sure scope is not lost when quote is created by admin.

Author: vo1

app/code/Magento/Shipping/Model/Shipping.php

@@ -273,7 +273,7 @@ public function collectRates(\Magento\Quote\Model\Quote\Address\RateRequest $req
      */
     private function prepareCarrier(string $carrierCode, RateRequest $request): AbstractCarrier
     {
-        $carrier = $this->isShippingCarrierAvailable($carrierCode)
+        $carrier = $this->isShippingCarrierAvailable($carrierCode, $request->getStoreId())
             ? $this->_carrierFactory->create($carrierCode, $request->getStoreId())
             : null;
         if (!$carrier) {
@@ -541,13 +541,15 @@ public function setCarrierAvailabilityConfigField($code = 'active')
      * Checks availability of carrier.
      *
      * @param string $carrierCode
+     * @param null|int $storeId
      * @return bool
      */
-    private function isShippingCarrierAvailable(string $carrierCode): bool
+    private function isShippingCarrierAvailable(string $carrierCode, ?int $storeId = null): bool
     {
         return $this->_scopeConfig->isSetFlag(
             'carriers/' . $carrierCode . '/' . $this->_availabilityConfigField,
-            \Magento\Store\Model\ScopeInterface::SCOPE_STORE
+            \Magento\Store\Model\ScopeInterface::SCOPE_STORE,
+            $storeId
         );
     }
 }