fix: Option description has sufficient color contrast in dark mode

[Al-Dani]

Description

Change on-hover text color of the description and tags in Selectable Option in dark mode so it meets sufficient color contrast.
Change affects Select, MultiSelect options with description and/or tags, Autosuggest options with tags, description and filteringTags.

Logic behind hover detection is the same as for the hover background color.

Related links, issue #, if available: AWSUI-10333

How has this been tested?

Manually.
Before:

After:

Review checklist

The following items are to be evaluated by the author(s) and the reviewer(s).

Correctness

• Changes include appropriate documentation updates.
• Changes are backward-compatible if not indicated, see CONTRIBUTING.md.
• Changes do not include unsupported browser features, see CONTRIBUTING.md.
• Changes were manually tested for accessibility, see accessibility guidelines.

Security

• If the code handles URLs: all URLs are validated through the checkSafeUrl function.

Testing

• Changes are covered with new/existing unit tests?
• Changes are covered with new/existing integration tests?

---

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov]

Codecov Report

Base: 92.98% // Head: 92.98% // Increases project coverage by +0.00% 🎉

Coverage data is based on head (a7e5dd1) compared to base (23f9839).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #670   +/-   ##
=======================================
  Coverage   92.98%   92.98%           
=======================================
  Files         574      574           
  Lines       16782    16796   +14     
  Branches     4632     4634    +2     
=======================================
+ Hits        15604    15618   +14     
  Misses       1101     1101           
  Partials       77       77           

Impacted Files	Coverage Δ
src/autosuggest/autosuggest-option.tsx	96.55% <ø> (ø)
src/select/parts/multiselect-item.tsx	100.00% <ø> (ø)
src/internal/components/option/index.tsx	96.77% <100.00%> (+0.22%)	⬆️
src/internal/components/option/option-parts.tsx	100.00% <100.00%> (ø)
src/select/parts/item.tsx	93.33% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.