[python][client] Clean up samples and CI (#17509)

* chore: Remove leftover Github action file

This was probably added by mistake. A similar file is active in
.github/workflows/samples-python-pydantic-v1-petstore.yaml.

* chore: Remove leftover VERSION from old python-experimental sample

* ci: Stop running Python integration tests in Circle CI

These Python clients are all tested with Github Actions already, which
is faster, more cleanly separated and only runs on modifications.

I'm not cleaning up the pydantic-v1 client, I expect it to be removed soon anyway.

* chore: Remove true from sample folder name

python-disallowAdditionalPropertiesIfNotPresent-true
-> python-disallowAdditionalPropertiesIfNotPresent

samples/client/echo_api/python-disallowAdditionalPropertiesIfNotPresent/docs/FormApi.md

@@ -0,0 +1,158 @@
+# openapi_client.FormApi
+
+All URIs are relative to *http://localhost:3000*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**test_form_integer_boolean_string**](FormApi.md#test_form_integer_boolean_string) | **POST** /form/integer/boolean/string | Test form parameter(s)
+[**test_form_oneof**](FormApi.md#test_form_oneof) | **POST** /form/oneof | Test form parameter(s) for oneOf schema
+
+
+# **test_form_integer_boolean_string**
+> str test_form_integer_boolean_string(integer_form=integer_form, boolean_form=boolean_form, string_form=string_form)
+
+Test form parameter(s)
+
+Test form parameter(s)
+
+### Example
+
+
+```python
+import openapi_client
+from openapi_client.rest import ApiException
+from pprint import pprint
+
+# Defining the host is optional and defaults to http://localhost:3000
+# See configuration.py for a list of all supported configuration parameters.
+configuration = openapi_client.Configuration(
+    host = "http://localhost:3000"
+)
+
+
+# Enter a context with an instance of the API client
+with openapi_client.ApiClient(configuration) as api_client:
+    # Create an instance of the API class
+    api_instance = openapi_client.FormApi(api_client)
+    integer_form = 56 # int |  (optional)
+    boolean_form = True # bool |  (optional)
+    string_form = 'string_form_example' # str |  (optional)
+
+    try:
+        # Test form parameter(s)
+        api_response = api_instance.test_form_integer_boolean_string(integer_form=integer_form, boolean_form=boolean_form, string_form=string_form)
+        print("The response of FormApi->test_form_integer_boolean_string:\n")
+        pprint(api_response)
+    except Exception as e:
+        print("Exception when calling FormApi->test_form_integer_boolean_string: %s\n" % e)
+```
+
+
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **integer_form** | **int**|  | [optional] 
+ **boolean_form** | **bool**|  | [optional] 
+ **string_form** | **str**|  | [optional] 
+
+### Return type
+
+**str**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/x-www-form-urlencoded
+ - **Accept**: text/plain
+
+### HTTP response details
+
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+**200** | Successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+
+# **test_form_oneof**
+> str test_form_oneof(form1=form1, form2=form2, form3=form3, form4=form4, id=id, name=name)
+
+Test form parameter(s) for oneOf schema
+
+Test form parameter(s) for oneOf schema
+
+### Example
+
+
+```python
+import openapi_client
+from openapi_client.rest import ApiException
+from pprint import pprint
+
+# Defining the host is optional and defaults to http://localhost:3000
+# See configuration.py for a list of all supported configuration parameters.
+configuration = openapi_client.Configuration(
+    host = "http://localhost:3000"
+)
+
+
+# Enter a context with an instance of the API client
+with openapi_client.ApiClient(configuration) as api_client:
+    # Create an instance of the API class
+    api_instance = openapi_client.FormApi(api_client)
+    form1 = 'form1_example' # str |  (optional)
+    form2 = 56 # int |  (optional)
+    form3 = 'form3_example' # str |  (optional)
+    form4 = True # bool |  (optional)
+    id = 56 # int |  (optional)
+    name = 'name_example' # str |  (optional)
+
+    try:
+        # Test form parameter(s) for oneOf schema
+        api_response = api_instance.test_form_oneof(form1=form1, form2=form2, form3=form3, form4=form4, id=id, name=name)
+        print("The response of FormApi->test_form_oneof:\n")
+        pprint(api_response)
+    except Exception as e:
+        print("Exception when calling FormApi->test_form_oneof: %s\n" % e)
+```
+
+
+
+### Parameters
+
+
+Name | Type | Description  | Notes
+------------- | ------------- | ------------- | -------------
+ **form1** | **str**|  | [optional] 
+ **form2** | **int**|  | [optional] 
+ **form3** | **str**|  | [optional] 
+ **form4** | **bool**|  | [optional] 
+ **id** | **int**|  | [optional] 
+ **name** | **str**|  | [optional] 
+
+### Return type
+
+**str**
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+ - **Content-Type**: application/x-www-form-urlencoded
+ - **Accept**: text/plain
+
+### HTTP response details
+
+| Status code | Description | Response headers |
+|-------------|-------------|------------------|
+**200** | Successful operation |  -  |
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+