Update write_ieee to use the new bellows API

[puddly]

Fixes #64

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

Attention: Patch coverage is 92.30769% with 1 line in your changes missing coverage. Please review.

Project coverage is 68.01%. Comparing base (b009196) to head (ea60892).
Report is 11 commits behind head on dev.

Files with missing lines	Patch %	Lines
universal_silabs_flasher/flash.py	66.66%	1 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##              dev      #87      +/-   ##
==========================================
+ Coverage   61.78%   68.01%   +6.22%     
==========================================
  Files          14       14              
  Lines        1748     1735      -13     
==========================================
+ Hits         1080     1180     +100     
+ Misses        668      555     -113     

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