fix: remove customMessageData from handleSubmit type declaration

[MartinCupela]

🎯 Goal

The arg customMessageData is not supported since v13.0.0 and these declarations falsely claimed that the custom message data were passed as a second argument to the handleSubmit function.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.89%. Comparing base (e5b528d) to head (c2ce742).
⚠️ Report is 2 commits behind head on release-v13.

Additional details and impacted files

@@               Coverage Diff               @@
##           release-v13    #2950      +/-   ##
===============================================
- Coverage        80.93%   80.89%   -0.04%     
===============================================
  Files              506      506              
  Lines            10558    10558              
  Branches          2413     2479      +66     
===============================================
- Hits              8545     8541       -4     
+ Misses            1883     1584     -299     
- Partials           130      433     +303     

☔ 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.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[oliverlaz]

hey @MartinCupela, please mention the BREAKING CHANGE in the PR description so it automatically appears in the changelog