ci: Refactor workflow versions to use 'latest' and remove env vars

[hzhangxyz]

This PR refactors the GitHub Actions workflows to simplify version management by removing explicit version environment variables in favor of the 'latest' alias.

Changes:

• Refactor: Removed NODE_LATEST_VERSION and PYTHON_LATEST_VERSION environment variables across all workflows.
• Update: Replaced usages of these variables with the literal string 'latest' in actions/setup-node, actions/setup-python, and astral-sh/setup-uv.
• Update: Modified cache keys (e.g., in jest.yml) to remove the dependency on the specific version environment variable.
• Fix: Corrected the bnf-pytest.yml workflow where the build job was incorrectly trying to access ${{ matrix.python-version }} (which is not available in that job context); it now correctly
  uses 'latest'.

[Copilot]

Pull request overview

This PR simplifies GitHub Actions workflow configuration by replacing explicit version environment variables (NODE_LATEST_VERSION and PYTHON_LATEST_VERSION) with the latest alias throughout all workflow files.

Key Changes:

• Removed NODE_LATEST_VERSION: '24' and PYTHON_LATEST_VERSION: '3.14' environment variables from all workflow files
• Updated actions/setup-node, actions/setup-python, and astral-sh/setup-uv to use python-version: latest or node-version: latest instead of environment variable references
• Fixed a bug in bnf-pytest.yml where the build job incorrectly referenced ${{ matrix.python-version }} (which doesn't exist in that job context)

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
.github/workflows/pytest.yml	Removed PYTHON_LATEST_VERSION env var and updated Python setup actions to use latest
.github/workflows/jest.yml	Removed NODE_LATEST_VERSION env var, updated Node setup to use latest, and simplified emsdk cache key
.github/workflows/egg-pytest.yml	Removed PYTHON_LATEST_VERSION env var and updated Python setup actions to use latest
.github/workflows/egg-jest.yml	Removed NODE_LATEST_VERSION env var and updated Node setup actions to use latest
.github/workflows/bnf-pytest.yml	Removed PYTHON_LATEST_VERSION env var and fixed incorrect matrix variable reference in build job
.github/workflows/bnf-jest.yml	Removed NODE_LATEST_VERSION env var and updated Node setup actions to use latest

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[Copilot]

The cache key for the emsdk cache has been simplified to remove the Node version component. However, this creates a mismatch with the jest job above (line 32), which still uses jest-em-cache-${{ runner.os }}-${{ matrix.node-version }} as its cache key. This means the npm job will not be able to reuse the cache created by the jest job, potentially impacting build performance. Consider aligning both cache keys to use the same pattern.