[FIX] setup.py: Exclude benchmark directory from the install

[ales-erjavec]

Issue

The benchmark directory is installed/included as a top level package in the build wheel files.

$ zipinfo -s Orange3-3.28.0-cp36-cp36m-macosx_10_6_intel.whl | tail -n 17
-rw-r--r--  2.0 unx     5325 b- defN 12-Mar-21 08:48 Orange3-3.28.0.data/data/share/help/en/orange3/htmlhelp/widgets/visualize/venndiagram.html
-rw-r--r--  2.0 unx     4933 b- defN 12-Mar-21 08:48 Orange3-3.28.0.data/data/share/help/en/orange3/htmlhelp/widgets/visualize/violinplot.html
-rw-r--r--  2.0 unx        0 b- defN 12-Mar-21 08:45 benchmark/__init__.py
-rw-r--r--  2.0 unx     5042 b- defN 12-Mar-21 08:45 benchmark/base.py
-rw-r--r--  2.0 unx     2109 b- defN 12-Mar-21 08:45 benchmark/bench_basic.py
-rw-r--r--  2.0 unx     1507 b- defN 12-Mar-21 08:45 benchmark/bench_domain.py
-rw-r--r--  2.0 unx     1976 b- defN 12-Mar-21 08:45 benchmark/bench_owkmeans.py
-rw-r--r--  2.0 unx     2016 b- defN 12-Mar-21 08:45 benchmark/bench_save.py
-rw-r--r--  2.0 unx     2023 b- defN 12-Mar-21 08:45 benchmark/bench_transform.py
-rw-r--r--  2.0 unx      488 b- defN 12-Mar-21 08:45 benchmark/bench_variable.py
-rw-r--r--  2.0 unx      378 b- defN 12-Mar-21 08:48 Orange3-3.28.0.dist-info/LICENSE
-rw-r--r--  2.0 unx     3354 b- defN 12-Mar-21 08:48 Orange3-3.28.0.dist-info/METADATA
-rw-r--r--  2.0 unx      109 b- defN 12-Mar-21 08:48 Orange3-3.28.0.dist-info/WHEEL
-rw-r--r--  2.0 unx      176 b- defN 12-Mar-21 08:48 Orange3-3.28.0.dist-info/entry_points.txt
-rw-r--r--  2.0 unx       17 b- defN 12-Mar-21 08:48 Orange3-3.28.0.dist-info/top_level.txt
?rw-rw-r--  2.0 unx   139730 b- defN 12-Mar-21 08:48 Orange3-3.28.0.dist-info/RECORD
1248 files, 34905215 bytes uncompressed, 25102177 bytes compressed:  28.1%

Description of changes

Explicit include only Orange package.

Includes

• Code changes
• Tests
• Documentation

[codecov]

Codecov Report

Merging #5392 (98aff47) into master (8d2429e) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #5392      +/-   ##
==========================================
- Coverage   86.33%   86.32%   -0.01%     
==========================================
  Files         302      302              
  Lines       61298    61298              
==========================================
- Hits        52922    52917       -5     
- Misses       8376     8381       +5