feat(datakit): Call node support for running after proxying (#4100)

* support for using call nodes after proxying

* adjust faq after testing

* Apply suggestions from code review

Co-authored-by: Diana <[email protected]>

---------

Co-authored-by: Diana <[email protected]>

Author: lena-larionova

app/_kong_plugins/datakit/index.md

@@ -633,7 +633,10 @@ For a complete example, see:
 
 ### Call node
 
-Send an HTTP request and retrieve the response.
+Send an HTTP request and retrieve the response. 
+
+{% new_in 3.13 %} The `call` node can be executed before or after proxying a request.
+For versions of {{site.base_gateway}} 3.12 or earlier, call nodes could only be executed before proxying; see [limitations](#limitations) for details.
 
 See the [configuration reference](/plugins/datakit/reference/#schema--config-nodes) and select `call` from the node object dropdown to see all node attributes.
 
@@ -757,9 +760,9 @@ See [Third-party auth](/plugins/datakit/examples/authenticate-third-party/) for
 
 #### Limitations
 
-Due to platform limitations, the `call` node can't be executed after proxying a
+In {{site.base_gateway}} 3.12 and earlier, the `call` node couldn't be executed after proxying a
 request, so attempting to configure the node using outputs from the upstream service
-response will yield an error:
+response would yield an error:
 
 ```yaml
 - name: CALL

app/gateway/datakit-flow-editor.md

@@ -23,6 +23,18 @@ related_resources:
     url: /gateway/datakit/
   - text: Datakit plugin reference
     url: /plugins/datakit/
+
+faqs:
+  - q: I've configured a call node in the response section, why is it throwing an error?
+    a: |
+      In {{site.base_gateway}} 3.12 and earlier, the `call` node couldn't be executed after proxying a request, and you would see the following error:
+
+      ```
+      invalid dependency (node #1 (CALL) -> node service_response): circular dependency
+      ```
+
+      This means that your data planes are running {{site.base_gateway}} 3.12 or earlier. 
+      Upgrade your data planes to 3.13 to use this functionality.
 ---
 
 In addition to the standard [{{site.base_gateway}} configuration tools](/tools/),