Update Portugal holidays: fix Carnival date

[DgRosa]

Proposed change

This aims to fix an issue with the current weekday of the Carnival holiday in Portugal.
It was set to happen on a Monday when it's always been a Tuesday.

There's not an official government document because Carnival is an optional holiday, there is however a Wikipedia entry with this information.

Closes #1692.

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)
• Dependency update (version deprecation/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

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

I've ran make pre-commit but got the following error message:

[sonarcloud]

Quality Gate passed

Issues
0 New issues

Measures
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud

[coveralls]

Pull Request Test Coverage Report for Build 7958673682

Details

• 0 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

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Totals
Change from base Build 7945701764:	0.0%
Covered Lines:	10547
Relevant Lines:	10547

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💛 - Coveralls

[arkid15r]

There's not an official government document because Carnival is an optional holiday, there is however a Wikipedia entry with this information.

Yeah, it'd be great to include an official reference if any.

🇵🇹 LGTM

@KJhellico any comments? This is quite small fix that could be included into today's release.

[KJhellico]

LGTM!