AzIntEngine: Use integer fill value for azint_count

azint_count is std::vector<uint32_t>; initialize it with 0u instead
of the float literal 0.0f.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

image_analysis/azint/AzIntEngine.cpp

@@ -9,4 +9,4 @@ azint_bins(integration.GetBinNumber()),
 npixel(integration.GetPixelToBin().size()),
 azint_sum(integration.GetBinNumber(), 0.0f),
 azint_sum2(integration.GetBinNumber(), 0.0f),
-azint_count(integration.GetBinNumber(), 0.0f){}
+azint_count(integration.GetBinNumber(), 0u){}