chore(ci): include python 3.14 into test suite

[o-santi]

What kind of change does this PR introduce?

Add python 3.14 into test suite in CI.

Additional context

We should define a deadline to remove 3.9 from the supported versions. October 2025 (this month) is officially last month of security support for 3.9 (per official docs), so we need to decide on a date for deprecation.

[grdsdev]

Regarding dropping support for 3.9, just decide on a date and post a discussion as we did for Node 18 announcing the support drop.

[o-santi]

It seems that the CI is also hitting #1252, while I wasn't able to do it manually -- most likely my environment was using the wrong version of python. We'll need to wait for the upstream fix of pydantic to get merged and published before using 3.14.

This PR can also serve the purpose of ensuring that this library is compatible with the new version release.

[coveralls]

Pull Request Test Coverage Report for Build 18505983618

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 93.928%

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Totals
Change from base Build 18355756900:	0.0%
Covered Lines:	8786
Relevant Lines:	9354

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💛 - Coveralls