Migrate Pelican setup to Python 3.14 + uv

[alehpineda]

Summary

• migrate dependency management from requirements/pip to uv (pyproject.toml + uv.lock)
• update GitHub Actions build/publish workflows to Python 3.14 and uv commands
• update README and CONTRIBUTING guides (EN/ES/PT) with uv-based local setup and Pelican commands

Validation

• uv sync --frozen
• uv run pelican content -o output -s pelicanconf.py
• uv run pelican --help

[Copilot]

Pull request overview

Migrates the Pelican site’s Python tooling from requirements.txt/pip to uv, updates CI workflows to use Python 3.14 + uv, and refreshes contributor docs to reflect the new setup.

Changes:

• Introduce pyproject.toml + uv.lock and remove requirements.txt.
• Update GitHub Actions build/publish workflows to use actions/setup-python@v5, Python 3.14, astral-sh/setup-uv, and uv sync/uv run.
• Update README/CONTRIBUTING guides (EN/ES/PT) with uv-based install and Pelican commands.

Reviewed changes

Copilot reviewed 9 out of 11 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
uv.lock	Adds uv lockfile pinning transitive dependencies and Python requirement.
requirements.txt	Removes legacy pip requirements file.
pyproject.toml	Defines project metadata + runtime dependencies and uv configuration.
README.md	Documents local development using uv sync --frozen and uv run pelican ....
README_es_MX.md	Updates setup instructions to use uv.
CONTRIBUTING.md	Updates setup instructions to use uv.
CONTRIBUTING_en_US.md	Updates setup instructions to use uv.
CONTRIBUTING_es_MX.md	Updates setup instructions to use uv.
CONTRIBUTING_pr_BR.md	Updates setup instructions to use uv.
.github/workflows/build.yml	CI build updated to Python 3.14 + uv.
.github/workflows/publish.yml	Publish workflow updated to Python 3.14 + uv for build/deploy steps.

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[Copilot]

Minor formatting in the shell comment: add a space after # so it renders/readability matches the other comments.

Suggested change

	#press ctrl+c to exit the local server
	# press ctrl+c to exit the local server

[Copilot]

This workflow pushes back to the repo (git push -f origin master). To make that reliable across org/repo settings, explicitly set job/workflow permissions: contents: write (otherwise GITHUB_TOKEN is often read-only by default and the push can fail).

[ChicoXXX]

LGTM