Adds prepare pre release flow. Closes #695

[Adam-it]

🎯 Aim

The aim of this PR is to introduce a new GitHub workflow which will prepare dev branch for running pre-release.
That way if we will want to perform a pre-release from a mobile it will be as simple as:

1. Run the pre-release workflow
2. This will open a PR that targets dev branch with updated patch version in package.json and npm-shrinkwrap.json. We should review it, to double-check, and merge as any other PR
3. Run pre-release workflow

That's it. No manual local checkout and updating versions on our own.

📷 Result

I don't have any images to show, but I already tested it on my fork.

• You may check the flow run here: https://github.com/Adam-it/vscode-viva/actions/runs/23413414115
• And this was the result PR: Pre-Release preparation Adam-it/vscode-viva#3

✅ What was done

• Added a PS script that bumps the patch version in package.json
• Updated package.json and npm-shrinkwrap.json formatting to 2 spaces - this change is a bit tricky. Currently, in package.json and npm-shrinkwrap.json, a single tab (4 spaces) is used for code formatting. Unfortunately, the PowerShell 7+ Convert-toJson method does not allow to set this and defaults to 2 spaces for formatting. So in order to have a clean PR with only changed version numbers I had to aling this formatting before hand to make it ready for first flow run
• Added a prepare pre-release flow

🔗 Related issue

Closes: #695

[Adam-it]

need to resolve conflicts after the minor release before we continue with this PR