Java: Python: Docs: Fix broken link (#6092)

### Motivation and Context
<!-- Thank you for your contribution to the semantic-kernel repo!
Please help reviewers and future users, providing the following
information:
  1. Why is this change required?
  2. What problem does it solve?
  3. What scenario does it contribute to?
  4. If it fixes an open issue, please link to the issue here.
-->
`https://openai.com/product` is failing `Check .md links` workflow.

### Description
<!-- Describe your changes, the overall approach, the underlying design.
These notes will help understanding how your code works. Thanks! -->

Revise links.


https://github.com/microsoft/semantic-kernel/actions/workflows/markdown-link-check.yml

Whitespace edits peformed by VS Code

### Contribution Checklist
<!-- Before submitting this PR, please make sure: -->

- [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 😄

python/README.md

@@ -17,7 +17,7 @@ or all of them:
 ## OpenAI / Azure OpenAI API keys
 
 Make sure you have an
-[OpenAI API Key](https://openai.com/product/) or
+[OpenAI API Key](https://platform.openai.com) or
 [Azure OpenAI service key](https://learn.microsoft.com/azure/cognitive-services/openai/quickstart?pivots=rest-api)
 
 Copy those keys into a `.env` file (see the `.env.example` file):