Fix Azure storage date header for SAS authentication

Only add date header for shared key authentication where it's required
for signature generation. SAS tokens are self-contained and don't need
the date header, which was causing test failures.

Author: moizpgedge

src/storage/azure/storage.c

@@ -131,12 +131,14 @@ storageAzureAuth(
     {
         // Set required headers
         httpHeaderPut(httpHeader, HTTP_HEADER_HOST_STR, this->host);
-        httpHeaderPut(httpHeader, HTTP_HEADER_DATE_STR, dateTime);
         httpHeaderPut(httpHeader, AZURE_HEADER_VERSION_STR, AZURE_HEADER_VERSION_VALUE_STR);
 
         // Shared key authentication
         if (this->keyType == storageAzureKeyTypeShared)
         {
+            // Date header is required for shared key authentication (used in signature generation)
+            httpHeaderPut(httpHeader, HTTP_HEADER_DATE_STR, dateTime);
+
             ASSERT(this->sharedKey != NULL);
 
             // Generate canonical headers