erpnext: refactor async to is_async (#15231)

diff --git a/erpnext/accounts/doctype/payment_request/payment_request.py b/erpnext/accounts/doctype/payment_request/payment_request.py
index e7371bd..24076a5 100644
--- a/erpnext/accounts/doctype/payment_request/payment_request.py
+++ b/erpnext/accounts/doctype/payment_request/payment_request.py
@@ -186,7 +186,7 @@
 			"now": True,
 			"attachments": [frappe.attach_print(self.reference_doctype, self.reference_name,
 				file_name=self.reference_name, print_format=self.print_format)]}
-		enqueue(method=frappe.sendmail, queue='short', timeout=300, async=True, **email_args)
+		enqueue(method=frappe.sendmail, queue='short', timeout=300, is_async=True, **email_args)
 
 	def get_message(self):
 		"""return message with payment gateway link"""
diff --git a/erpnext/erpnext_integrations/doctype/shopify_log/shopify_log.py b/erpnext/erpnext_integrations/doctype/shopify_log/shopify_log.py
index e6e6579..0c821e0 100644
--- a/erpnext/erpnext_integrations/doctype/shopify_log/shopify_log.py
+++ b/erpnext/erpnext_integrations/doctype/shopify_log/shopify_log.py
@@ -43,11 +43,11 @@
 	}).insert(ignore_permissions=True)
 
 	frappe.db.commit()
-	frappe.enqueue(method=event_mapper[event], queue='short', timeout=300, async=True, 
+	frappe.enqueue(method=event_mapper[event], queue='short', timeout=300, is_async=True, 
 		**{"order": data, "request_id": log.name})
 
 @frappe.whitelist()
 def resync(method, name, request_data):
 	frappe.db.set_value("Shopify Log", name, "status", "Queued", update_modified=False)
-	frappe.enqueue(method=method, queue='short', timeout=300, async=True, 
+	frappe.enqueue(method=method, queue='short', timeout=300, is_async=True, 
 		**{"order": json.loads(request_data), "request_id": name})
diff --git a/erpnext/hr/doctype/salary_slip/salary_slip.py b/erpnext/hr/doctype/salary_slip/salary_slip.py
index a009fb0..19233ba 100644
--- a/erpnext/hr/doctype/salary_slip/salary_slip.py
+++ b/erpnext/hr/doctype/salary_slip/salary_slip.py
@@ -526,7 +526,7 @@
 				"reference_name": self.name
 				}
 			if not frappe.flags.in_test:
-				enqueue(method=frappe.sendmail, queue='short', timeout=300, async=True, **email_args)
+				enqueue(method=frappe.sendmail, queue='short', timeout=300, is_async=True, **email_args)
 			else:
 				frappe.sendmail(**email_args)
 		else: