prompt flow service: wrong version (1.11.0) in requirements.txt. Service has been updated to 1.15.0

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### This issue is for a: (mark with an `x`)
```
- [x] bug report -> please search issues before submitting
- [ ] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)
```

### Minimal steps to reproduce
> follow the instructions https://learn.microsoft.com/en-us/azure/ai-studio/tutorials/copilot-sdk-evaluate-deploy
download python packages
cd C:\work\Azure-Samples\rag-data-openai-python-promptflow\tutorial\copilot_flow
pip install -r requirements.txt

this installs promptflow[azure] and promptflow in version 1.11.0, however the service is already at 1.15.0

### Any log messages given by the failure
>(.venv) PS C:\work\Azure-Samples\rag-data-openai-python-promptflow\tutorial> python evaluate.py
[2024-09-03 15:38:12 +0200][promptflow._sdk._orchestrator.run_submitter][INFO] - Upload run to cloud: True
[2024-09-03 15:38:16 +0200][promptflow][WARNING] - Prompt flow service is running on port 23333, but the version is not the same as local sdk version 1.11.0. The service version is 1.15.0.
Starting prompt flow service...
[2024-09-03 15:38:30 +0200][promptflow][WARNING] - Prompt flow service is running on port 23333, but the version is not the same as local sdk version 1.11.0. The service version is 1.15.0.
[2024-09-03 15:38:30 +0200][promptflow][WARNING] - Prompt flow service is not healthy. Kindly reminder: If you have previously upgraded the prompt flow package , please double-confirm that you have run 'pf service stop' to stop the prompt flowservice before proceeding with the upgrade. Otherwise, you may encounter unexpected environmental issues or inconsistencies between the version of running prompt flow service and the local prompt flow version. Alternatively, you can use the 'pf upgrade' command to proceed with the upgrade process for the prompt flow package.
[2024-09-03 15:38:30 +0200][promptflow][WARNING] - Prompt flow service is running on port 23333, but the version is not the same as local sdk version 1.11.0. The service version is 1.15.0.
[2024-09-03 15:38:30 +0200][promptflow][WARNING] - Prompt flow service is not healthy, please check the logs for more details; traces might not be exported correctly.
T

### Expected/desired behavior
> update requirements.txt to use 1.15.0 (or do not specify version number)
or update manually
pip install promptflow[azure]==1.15.0
pip install promptflow==1.15.0

### OS and Version?
> Windows 7, 8 or 10. Linux (which distribution). macOS (Yosemite? El Capitan? Sierra?)

### Versions
>

### Mention any other details that might be useful

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