[Docs]: axe-devtools color contrast a11y reports

### Code of conduct

- [X] I agree to follow this project's code of conduct.

### Impacted component(s)

Documentation

### Description of the requested feature

While testing some other stuff I observed that there are a lot of warnings from axe about color contrast for `code` tags.
Can we increase the contrast by using `spectrum-blue-900` instead of `spectrum-blue-700` and pass the contrast threshold for both dark and light variants and for all theme variations?

### Mockups or screenshots


### Implementation notes or ideas

_No response_

Start by locating the documentation styling for code tags and the use of spectrum-blue-700. Replace it with spectrum-blue-900 if appropriate, then check the axe color-contrast warnings for both dark and light variants across all theme variations; done means the reported contrast issues pass.

Written by the indexing model from the issue text.