Set-up the build and release workflows

[azatsarynnyy]

https://redhat.atlassian.net/browse/CRW-10664

• added the publishPlugin Gradle Task, provided by the JetBrains Team, and slightly adapted to our plugin
• added the Build workflow that is triggered on PRs and on each push to main. After pushing to main, prepare the release draft
• added the Release workflow that handles the release process based on the previously prepared draft release
• added the release instructions

[Copilot]

Pull request overview

Sets up build/release automation to package and publish the JetBrains Toolbox plugin (incl. Marketplace publishing support).

Changes:

• Adds a Gradle “publish” build-logic plugin that packages and uploads the plugin ZIP to JetBrains Marketplace.
• Introduces GitHub Actions workflows to build artifacts, create a draft release, and publish on release events.
• Centralizes the plugin “vendor” value via Gradle extra properties.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
plugin/build.gradle.kts	Applies the new publish plugin and defines a vendor extra property.
gradle/libs.versions.toml	Adds JetBrains Marketplace REST client dependency coordinates/version.
build-logic/src/main/kotlin/toolbox/buildlogic/ToolboxGenerateJsonExtension.kt	Reads vendor from project extra properties when generating extension.json.
build-logic/src/main/kotlin/toolbox/buildlogic/PublishToolboxPlugin.kt	New packaging + Marketplace publishing tasks.
build-logic/build.gradle.kts	Registers the new Gradle plugin and adds Marketplace client dependency.
.github/workflows/build.yml	New CI build + artifact + draft release workflow.
.github/workflows/release.yml	New release-triggered Marketplace publish + GitHub release asset upload workflow.
.DS_Store	Adds a macOS metadata file (should not be committed).

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[azatsarynnyy]

@rgrunber please, take a look

[rgrunber]

When I ran the build on my fork, the build job succeeded just fine and also generated a new draft release. However the release job failed with :

FAILURE: Build failed with an exception.
4 actionable tasks: 4 executed

* What went wrong:
A problem occurred configuring project ':plugin'.
> Could not create task ':plugin:publishPlugin'.
   > Cannot get property 'vendor' on extra properties extension as it does not exist

Is this expected, since I didn't provide a proper token or a missing property ?

[azatsarynnyy]

@rgrunber
I fixed the release job.
Now, it should fail with
Environment variable JETBRAINS_MARKETPLACE_PUBLISH_TOKEN is not set
🙂

Also, in the fork, I tested skipping uploading to the Marketplace
https://github.com/azatsarynnyy/devspaces-toolbox-plugin/releases/tag/v0.0.3

Upload to the Marketplace is straightforward. Will be tested when we release the next version.

Added the Release instructions to the README.md

[rgrunber]

I see it works on your fork, so 👍 , but for some reason mine was still showing the same error.