[MNT] Revert #6737

[ales-erjavec]

Issue

======================================================================
FAIL: test_remove_openpyxl_temp_solution (test_openpyxl_patch.TestRemoveTemporarySolution)
When this test starts to fail revert https://github.com/biolab/orange3/pull/6737
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Traceback (most recent call last):
  File "D:\a\orange3\orange3\.tox\orange-released\Lib\site-packages\Orange\misc\tests\test_openpyxl_patch.py", line 11, in test_remove_openpyxl_temp_solution
    self.assertLessEqual(
AssertionError: [3, 1, 3] not less than or equal to [3, 1, 2]

----------------------------------------------------------------------

Per the test comment reverting the openpyxl temp solution

Description of changes

Revert #6737

Includes

• [X] Code changes
• [ ] Tests
• [ ] Documentation

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 88.27%. Comparing base (ce27d18) to head (0b7ca11).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #6816 +/- ## ========================================== + Coverage 88.24% 88.27% +0.03% ========================================== Files 327 326 -1 Lines 71342 71261 -81 ========================================== - Hits 62954 62907 -47 + Misses 8388 8354 -34 ```