Switch from `yarn` to `pnpm`, improve workflows, add provenance to published package

[flevi29]

Pull Request

Related issue

Fixes #1660

What does this PR do

• switches package manager to pnpm
• updates and shortens GitHub actions regarding the setup of Node.js with the help of composite actions
  • https://pnpm.io/continuous-integration#github-actions
  • https://docs.github.com/en/actions/sharing-automations/creating-actions/creating-a-composite-action
• adds provenance to published package
  • https://docs.npmjs.com/generating-provenance-statements
  • https://github.blog/security/supply-chain-security/introducing-npm-package-provenance/
  • https://docs.github.com/en/actions/use-cases-and-examples/publishing-packages/publishing-nodejs-packages#publishing-packages-to-the-npm-registry

PR checklist

Please check if your PR fulfills the following requirements:

• [x] Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
• [x] Have you read the contributing guidelines?
• [x] Have you made sure that the title is accurate and descriptive of the changes?

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