🐛 Enable --keyboard-selected class to the YearPicker irrespective of the availability of selected prop

[balajis-qb]

Description

Linked issue: #5669

Problem
As I mentioned in the ticket, we're not applying --keyboard-selected class over the active year of YearPicker, when there is no selected year set by default.

Changes
I just removed the guard that prevent applying --keyboard-selected class when the selected prop is not available.

Contribution checklist

• I have followed the contributing guidelines.
• I have added sufficient test coverage for my changes.
• I have formatted my code with Prettier and checked for linting issues with ESLint for code readability.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.14%. Comparing base (6e0b763) to head (38eb9c1).
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5670      +/-   ##
==========================================
+ Coverage   97.11%   97.14%   +0.03%     
==========================================
  Files          30       30              
  Lines        3363     3364       +1     
  Branches     1404     1404              
==========================================
+ Hits         3266     3268       +2     
+ Misses         97       96       -1     

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