deprecate retry_on_eintr

[noviluni]

This function is not used, is not tested and is not documented, so we should probably remove it.

It was introduced to be used in test_commands.py but is not used anymore (ref: 6217f10)

[codecov]

Codecov Report

Merging #4683 into master will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #4683      +/-   ##
==========================================
+ Coverage   85.12%   85.13%   +0.01%     
==========================================
  Files         162      162              
  Lines        9718     9719       +1     
  Branches     1438     1438              
==========================================
+ Hits         8272     8274       +2     
  Misses       1186     1186              
+ Partials      260      259       -1     

Impacted Files	Coverage Δ
scrapy/utils/python.py	85.45% <100.00%> (+0.08%)	⬆️
scrapy/utils/trackref.py	85.71% <0.00%> (+2.85%)	⬆️

[GGXXLL]

Scrapyd-client use this function in scrapyd-deploy?

[Gallaecio]

In that case they can copy it into their code.