Update release workflow

[AndrewFerr]

• Switch from yarn classic to pnpm
• Use NPM Trusted Publishing, and use the built-in pnpm publish command to publish instead of the JS-DevTools/npm-publish action
  • This requires the package's settings on npmjs.com to have configured this workflow as a Trusted Publisher. See https://docs.npmjs.com/trusted-publishers#for-github-actions
• Create the GitHub release with gh release create instead of the actions/create-release action (with the intention of reducing dependencies on third-party actions)
• Analyze the workflow file with zizmor

[github-advanced-security]

You are seeing this message because GitHub Code Scanning has recently been set up for this repository, or this pull request contains the workflow file for the Code Scanning tool.

What Enabling Code Scanning Means:

• The 'Security' tab will display more code scanning analysis results (e.g., for the default branch).
• Depending on your configuration and choice of analysis tool, future pull requests will be annotated with code scanning analysis results.
• You will be able to see the analysis results for the pull request's branch on this overview once the scans have completed and the checks have passed.

For more information about GitHub Code Scanning, check out the documentation.

[AndrewFerr]

The Trusted Publishing workflow is based on what's done for matrix-appservice-bridge & matrix-appservice-node.

The zizmor workflow is based on what's done for Element Web.