fix: preserve DatePickerInput invalid state

[adamalston]

Closes #21035

Preserved DatePickerInput invalid state when DatePicker was not invalid.

Changelog

Changed

• Preserved DatePickerInput invalid state when DatePicker was not invalid.

Testing / Reviewing

yarn test packages/react/src/components/DatePicker/DatePicker-test.js

PR Checklist

As the author of this PR, before marking ready for review, confirm you:

• Reviewed every line of the diff
• Updated documentation and storybook examples
• Wrote passing tests that cover this change
• Addressed any impact on accessibility (a11y)
• Tested for cross-browser consistency
• Validated that this code is ready for review and status checks should pass

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.93%. Comparing base (597001a) to head (78f771f).
⚠️ Report is 58 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #22005      +/-   ##
==========================================
+ Coverage   94.90%   94.93%   +0.02%     
==========================================
  Files         541      541              
  Lines       45253    45256       +3     
  Branches     6359     6387      +28     
==========================================
+ Hits        42949    42965      +16     
+ Misses       2172     2159      -13     
  Partials      132      132              

Flag	Coverage Δ
main-packages	89.17% <100.00%> (+0.01%)	⬆️
web-components	97.70% <ø> (ø)

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[maradwan26]

LGTM