[FIX] owfeaturestatistics: Fix implicit int conversion error on resize

[ales-erjavec]

Issue

Feature Statistics widget raises an error on Python 3.10 (warning in Python 3.9) on widget resize due to implicit conversion to int.

----------------------------- TypeError Exception -----------------------------
Traceback (most recent call last):
  File "/home/ales/devel/orange3/Orange/widgets/data/owfeaturestatistics.py", line 687, in bind_histogram_aspect_ratio
    self.verticalHeader().setDefaultSectionSize(effective_height)
TypeError: setDefaultSectionSize(self, int): argument 1 has unexpected type 'float'
-------------------------------------------------------------------------------

Description of changes

Includes

• Code changes
• Tests
• Documentation

[codecov]

Codecov Report

Merging #5799 (def5b0d) into master (f7b522f) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #5799   +/-   ##
=======================================
  Coverage   86.12%   86.13%           
=======================================
  Files         316      316           
  Lines       66386    66386           
=======================================
+ Hits        57176    57181    +5     
+ Misses       9210     9205    -5     

[markotoplak]

Thanks!