text: Title: font "sans serif" no longer working
  Body: ### Checklist
  
  - [x] I have searched the [existing issues](https://github.com/streamlit/streamlit/issues) for similar issues.
  - [x] I added a very descriptive title to this issue.
  - [x] I have provided sufficient information below to help reproduce this issue.
  
  ### Summary
  
  When adding a `config.toml` with the font set to `"sans serif"` explicitly, as suggested [in the documentation](https://docs.streamlit.io/develop/concepts/configuration/theming#font), a **serif** font is used instead.
  ```
  [theme]
  font = "sans serif"
  ```
  
  This can be fixed by
  * omitting the `font` since sans-serif it is the default
  * using `"sans-serif"` (with a dash)
  
  It seems as if the font name was changed from `"sans serif"` to `"sans-serif"` without a matching change in the documentation.
  This change seems to have been introduced in version 14.3.
  
  ### Reproducible Code Example
  
  ```Python
  
  ```
  
  ### Steps To Reproduce
  
  _No response_
  
  ### Expected Behavior
  
  _No response_
  
  ### Current Behavior
  
  _No response_
  
  ### Is this a regression?
  
  - [x] Yes, this used to work in a previous version.
  
  ### Debug info
  
  - Streamlit version:
  - Python version:
  - Operating System:
  - Browser:
  
  
  ### Additional Information
  
  _No response_