Remove pkg_resources usage

[Laerte]

Fix #5956

Removed code for checking setup_tools version since we are checking for a version from 2015

[codecov]

Codecov Report

Merging #5958 (f22f882) into master (fae5538) will increase coverage by 46.48%.
The diff coverage is 50.00%.

❗ Current head f22f882 differs from pull request most recent head 82cf00b. Consider uploading reports for the commit 82cf00b to get more accurate results

@@             Coverage Diff             @@
##           master    #5958       +/-   ##
===========================================
+ Coverage   42.36%   88.84%   +46.48%     
===========================================
  Files         162      162               
  Lines       11206    11206               
  Branches     1825     1825               
===========================================
+ Hits         4747     9956     +5209     
+ Misses       6103      965     -5138     
+ Partials      356      285       -71     

Impacted Files	Coverage Δ
scrapy/cmdline.py	67.96% <50.00%> (+67.96%)	⬆️

... and 140 files with indirect coverage changes

[wRAR]

Thanks!