Remove deprecated `fix-encoding-pragma`, add `pyupgrade`

[PPsyrius]

Proposed change

This PR switches out fix-encoding-pragma hook for pyupgrade.

I noticed that the fix-encoding-pragma used in make pre-commit is listed as deprecated, as seen here:

As written in pre-commit-hooks pypl page:

fix-encoding-pragma Deprecated since py2 is EOL - use pyupgrade instead.

Add # -- coding: utf-8 -- to the top of python files. To remove the coding pragma pass --remove (useful in a python3-only codebase)

Type of change

• [ ] New country/market holidays support (thank you!)
• [ ] Supported country/market holidays update (calendar discrepancy fix, localization)
• [ ] Existing code/documentation/test/process quality improvement (best practice, cleanup, refactoring, optimization)
• [x] Dependency update (version deprecation/pin/upgrade)
• [ ] Bugfix (non-breaking change which fixes an issue)
• [ ] Breaking change (a code change causing existing functionality to break)
• [ ] New feature (new python-holidays functionality in general)

Checklist

• [x] I've followed the contributing guidelines
• [x] I've run make pre-commit, it didn't generate any changes
• [x] I've run make test, all tests passed locally

[PPsyrius]

Unlike the pre-commit results here, I can ascertain that these changes run correctly on my machine.

[KJhellico]

It's great update! But we also need to fix tests/test_i10n.py.

[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[codecov[bot]]

Codecov Report

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

Project coverage is 100.00%. Comparing base (34dc910) to head (2ddb2c3). Report is 2 commits behind head on dev.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #2007 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 188 188 Lines 11409 11409 Branches 1791 1791 ========================================= Hits 11409 11409 ```

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