build(python): change extra names to comply with PEP 685 (#446)

[mdonadoni]

Since pip>=23.3.0, non-normalised extra names are ignored, so
snakemake_reports is changed to snakemake-reports. The former name
is kept for backward compatibility with older versions of pip.

Before

$ pip install --upgrade pip
$ pip install '.[snakemake-reports]' | grep WARN
WARNING: reana-commons 0.9.7 does not provide the extra 'snakemake-reports'
$ pip install '.[snakemake_reports]' | grep WARN
WARNING: reana-commons 0.9.7 does not provide the extra 'snakemake-reports'

After

$ pip install --upgrade pip
$ pip install '.[snakemake_reports]' | grep WARN
$ pip install '.[snakemake-reports]' | grep WARN

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 36.33%. Comparing base (b4a81d5) to head (904178f).

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #446   +/-   ##
=======================================
  Coverage   36.33%   36.33%           
=======================================
  Files          26       26           
  Lines        1577     1577           
=======================================
  Hits          573      573           
  Misses       1004     1004