Remove textdomain from calendar block

[kebbet]

Description

Gutenberg text domain was introduced in core, this PR removes that text domain.
Closes: #36499
Core ticket: https://core.trac.wordpress.org/ticket/54444#comment:4

How has this been tested?

Screenshots

Types of changes

Checklist:

• My code is tested.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• I've tested my changes with keyboard and screen readers.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR (please manually search all *.native.js files for terms that need renaming or removal).

[github-actions]

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[Mamaduka]

The change looks good. Thanks for contributing, @kebbet.

[kebbet]

Thanks for accepting. Will this change be back-ported to WordPress 5.9? @Mamaduka

[Mamaduka]

Yes, it will be back-ported.