Fix error message InvocationMode typo in converter.py

[pankajkoti]

Following up on PR #2267, fix a typo in the error message suggesting to use InvocationMode.SUBPROCESS

related: #2267

[netlify]

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🔨 Latest commit	d7568cb
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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.01%. Comparing base (4cfac69) to head (d7568cb).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2270   +/-   ##
=======================================
  Coverage   98.01%   98.01%           
=======================================
  Files         100      100           
  Lines        6414     6414           
=======================================
  Hits         6287     6287           
  Misses        127      127           

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