fix: remove schema validation from feature release flow

[lechnerc77]

Description

The GitHub Action workflow currently fails (see https://github.com/radius-project/radius/actions/runs/7183715348) due to the usage of preview features in the devcontainer feature schema (for details see PR #6930)
This PR contains a fix to allow the release of the devcontainer feature even when suing preview features in the schema.

Type of change

• This pull request is a minor refactor, code cleanup, test improvement, or other maintenance task and doesn't change the functionality of Radius (issue link optional).

Fixes: n/a

Auto-generated summary

🤖[deprecated] Generated by Copilot at 184d5c9

Summary

🛠️🚀🐳

Disable schema validation for devcontainer feature release workflow. This fixes a compatibility issue with a preview GitHub Actions feature and allows the workflow to run on pull requests from forks.

pull_request_target
Preview feature, no schema
Workflow runs in fall

Walkthrough

• Disable schema validation for GitHub Actions workflow to use preview feature pull_request_target (link)

[lechnerc77]

@rynowak as announced in Discord https://discord.com/channels/1113519723347456110/1165003485457166346/1184164968426373130

[rynowak]

Thanks, I agree this is the right fix for now 👍 thanks for following-up.

[radius-functional-tests]

Radius functional test overview

🔍 Go to test action run

Name	Value
Repository	lechnerc77/radius
Commit ref	184d5c9
Unique ID	785e214d06
Image tag	pr-785e214d06

Click here to see the list of tools in the current test run

• gotestsum 1.10.0
• KinD: v0.20.0
• Dapr: 1.12.0
• Azure KeyVault CSI driver: 1.4.2
• Azure Workload identity webhook: 1.1.0
• Bicep recipe location ghcr.io/radius-project/dev/test/functional/shared/recipes/<name>:pr-785e214d06
• Terraform recipe location http://tf-module-server.radius-test-tf-module-server.svc.cluster.local/<name>.zip (in cluster)
• applications-rp test image location: ghcr.io/radius-project/dev/applications-rp:pr-785e214d06
• controller test image location: ghcr.io/radius-project/dev/controller:pr-785e214d06
• ucp test image location: ghcr.io/radius-project/dev/ucpd:pr-785e214d06
• deployment-engine test image location: ghcr.io/radius-project/deployment-engine:latest

Test Status

⌛ Building Radius and pushing container images for functional tests...
✅ Container images build succeeded
⌛ Publishing Bicep Recipes for functional tests...
✅ Recipe publishing succeeded
⌛ Starting datastoresrp functional tests...
⌛ Starting kubernetes functional tests...
⌛ Starting ucp functional tests...
⌛ Starting samples functional tests...
⌛ Starting msgrp functional tests...
⌛ Starting shared functional tests...
⌛ Starting daprrp functional tests...
✅ kubernetes functional tests succeeded
✅ msgrp functional tests succeeded
✅ ucp functional tests succeeded
✅ samples functional tests succeeded
✅ daprrp functional tests succeeded
✅ datastoresrp functional tests succeeded
✅ shared functional tests succeeded

[rynowak]

I logged an issue here: devcontainers/action#205 we'll see what they say.