Add support for configuring Splunk sourcetype in Custom Destinations

.generator/schemas/v2/openapi.yaml

@@ -17420,6 +17420,16 @@ components:
             Must have HTTPS scheme and forwarding back to Datadog is not allowed.
           example: https://example.com
           type: string
+        sourcetype:
+          description: |-
+            The Splunk sourcetype for the events sent to this Splunk destination.
+
+            If absent, the default sourcetype `_json` is used. If set to null, the `sourcetype`
+            field is omitted from the Splunk HEC payload entirely. Otherwise, the provided string
+            value is used as the sourcetype.
+          example: my-source
+          nullable: true
+          type: string
         type:
           $ref: "#/components/schemas/CustomDestinationForwardDestinationSplunkType"
       required:
@@ -17695,6 +17705,16 @@ components:
             Must have HTTPS scheme and forwarding back to Datadog is not allowed.
           example: https://example.com
           type: string
+        sourcetype:
+          description: |-
+            The Splunk sourcetype for the events sent to this Splunk destination.
+
+            If absent, the default sourcetype `_json` is used. If set to null, the `sourcetype`
+            field is omitted from the Splunk HEC payload entirely. Otherwise, the provided string
+            value is used as the sourcetype.
+          example: my-source
+          nullable: true
+          type: string
         type:
           $ref: "#/components/schemas/CustomDestinationResponseForwardDestinationSplunkType"
       required:

cassettes/features/v2/logs_custom_destinations/Create-a-Splunk-custom-destination-with-a-null-sourcetype-returns-OK-response.frozen

@@ -0,0 +1 @@
+2026-03-25T16:23:47.455Z

cassettes/features/v2/logs_custom_destinations/Create-a-Splunk-custom-destination-with-a-sourcetype-returns-OK-response.frozen

@@ -0,0 +1 @@
+2026-03-25T16:23:49.008Z

cassettes/features/v2/logs_custom_destinations/Create-a-Splunk-custom-destination-with-an-empty-string-sourcetype-returns-OK-response.frozen

@@ -0,0 +1 @@
+2026-03-25T16:23:50.210Z

cassettes/features/v2/logs_custom_destinations/Create-a-Splunk-custom-destination-with-an-invalid-sourcetype-returns-Bad-Request-response.frozen

@@ -0,0 +1 @@
+2026-03-25T16:23:51.766Z

cassettes/features/v2/logs_custom_destinations/Create-a-Splunk-custom-destination-without-a-sourcetype-returns-OK-response.frozen

@@ -0,0 +1 @@
+2026-03-25T16:23:52.120Z

cassettes/features/v2/logs_custom_destinations/Update-a-Splunk-custom-destination-s-attributes-preserves-the-absent-sourcetype-returns-OK-response.frozen

@@ -0,0 +1 @@
+2026-03-25T16:23:55.981Z

cassettes/features/v2/logs_custom_destinations/Update-a-Splunk-custom-destination-s-destination-preserves-the-null-sourcetype-returns-OK-response.frozen

@@ -0,0 +1 @@
+2026-03-25T16:23:59.087Z