chore(workflow): add step in the release workflow to check if all packages exist on npm

[myrtasakellariou]

📄 Description

Added a step in the release workflow (after dry-run) that creates the changesets.json and runs a script that checks if each included package already exists on npm. Tested locally with a fake changesets.json.

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🔮 Design review

• Design review done
• No design review needed

🧪 Visual regression tests

• Visual changes detected and approved (Check this box if VRT fails and changes are intentional)

📝 Checklist

• ✅ My code follows the style guidelines of this project
• 🛠️ I have performed a self-review of my own code
• 📄 I have made corresponding changes to the documentation
• ⚠️ My changes generate no new warnings or errors
• 🧪 I have added tests that prove my fix is effective or that my feature works
• ✔️ New and existing unit tests pass locally with my changes

[changeset-bot]

⚠️ No Changeset found

Latest commit: 070ceaa

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[oliverschuerch]

Suggested change

	- name: Check release packages exist on npm
	# Trusted publishing on the public npm registry requires the package
	# to already exist before we release it with the "trusted publishing" method.
	# New packages must first be published manually with a placeholder
	# version (e.g. 0.0.0), then configured for trusted publishing on npmjs.com.
	# This check fails fast if a queued package hasn't been bootstrapped yet.
	- name: Verify packages to release exist on the public npm registry

Alternatively, you could add the information about the placeholder package with version 0.0.0 in the check-packages-on-npm.mjs script.
But I think it would be helpful to know, it can be a dummy package initially, just to configure trusted publishing, before the "real" package will be released through the trusted publishing mechanism by our release workflow.