Bump Kotlin to 2.3.0

[lppedd]

As per title.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.93%. Comparing base (79b80e1) to head (387d006).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main     #155   +/-   ##
=========================================
  Coverage     85.93%   85.93%           
  Complexity      216      216           
=========================================
  Files            29       29           
  Lines           633      633           
  Branches        117      117           
=========================================
  Hits            544      544           
  Misses           60       60           
  Partials         29       29           

Flag	Coverage Δ
unittests	85.93% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[petertrr]

LGTM, thanks!