docs: allow boto3_session parameter to be passed through decorator

Author: Tom McCarthy

Diff for: aws_lambda_powertools/utilities/batch/sqs.py

@@ -150,6 +150,7 @@ def sqs_batch_processor(
     record_handler: Callable,
     config: Optional[Config] = None,
     suppress_exception: bool = False,
+    boto3_session: Optional[boto3.session.Session] = None,
 ):
     """
     Middleware to handle SQS batch event processing
@@ -168,6 +169,8 @@ def sqs_batch_processor(
             botocore config object
     suppress_exception: bool, optional
         Supress exception raised if any messages fail processing, by default False
+    boto3_session : boto3.session.Session, optional
+            Boto3 session to use for AWS API communication
 
     Examples
     --------
@@ -188,7 +191,9 @@ def sqs_batch_processor(
 
     """
     config = config or Config()
-    processor = PartialSQSProcessor(config=config, suppress_exception=suppress_exception)
+    session = boto3_session or boto3.session.Session()
+
+    processor = PartialSQSProcessor(config=config, suppress_exception=suppress_exception, boto3_session=session)
 
     records = event["Records"]