Python: Remove old references of plugin import (microsoft#10462)

### Motivation and Context

We had two places in code that showed how to perform a plugin import
using old code - `kernel.import_plugin...`.

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### Description

Removes old old comments, replacing it with the current
`kernel.add_plugin(...)`.

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### Contribution Checklist

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- [X] The code builds clean without any errors or warnings
- [X] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [X] All unit tests pass, and I have added new tests where possible
- [X] I didn't break anyone 😄

Author: moonbox3

python/samples/concepts/filtering/auto_function_invoke_filters.py

@@ -1,7 +1,6 @@
 # Copyright (c) Microsoft. All rights reserved.
 
 import asyncio
-import os
 
 from semantic_kernel import Kernel
 from semantic_kernel.connectors.ai import FunctionChoiceBehavior
@@ -29,10 +28,7 @@
 # Note: the underlying gpt-35/gpt-4 model version needs to be at least version 0613 to support tools.
 kernel.add_service(OpenAIChatCompletion(service_id="chat"))
 
-plugins_directory = os.path.join(__file__, "../../../../../prompt_template_samples/")
 # adding plugins to the kernel
-# the joke plugin in the FunPlugins is a semantic plugin and has the function calling disabled.
-# kernel.import_plugin_from_prompt_directory("chat", plugins_directory, "FunPlugin")
 # the math plugin is a core plugin and has the function calling enabled.
 kernel.add_plugin(MathPlugin(), plugin_name="math")
 kernel.add_plugin(TimePlugin(), plugin_name="time")

python/samples/getting_started/05-using-the-planner.ipynb

@@ -435,7 +435,7 @@
     "    Description: EmailPlugin provides a set of functions to send emails.\n",
     "\n",
     "    Usage:\n",
-    "        kernel.import_plugin_from_object(EmailPlugin(), plugin_name=\"email\")\n",
+    "        kernel.add_plugin(EmailPlugin(), plugin_name=\"email\")\n",
     "\n",
     "    Examples:\n",
     "        {{email.SendEmail}} => Sends an email with the provided subject and body.\n",
@@ -581,7 +581,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.12.6"
+   "version": "3.12.7"
   }
  },
  "nbformat": 4,