Fix issues with box handlers

[Rexios80]

No description provided.

[codecov]

Codecov Report

Attention: Patch coverage is 92.85714% with 2 lines in your changes missing coverage. Please review.

Project coverage is 93.89%. Comparing base (d5bde6f) to head (4fe8cb4).
Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
.../lib/src/isolate/handler/isolated_box_handler.dart	85.71%	1 Missing ⚠️
...lib/src/isolate/handler/isolated_hive_handler.dart	83.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #90      +/-   ##
==========================================
- Coverage   93.95%   93.89%   -0.06%     
==========================================
  Files          52       52              
  Lines        2315     2326      +11     
==========================================
+ Hits         2175     2184       +9     
- Misses        140      142       +2     

☔ 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.