Refactor workflow, run on main (#251)

* Refactor workflow

- Rename workflow to 'Build'
- Add push trigger on main branch
- Cancel workflow only when the run is NOT on `main` branch
- Update Gradle setup

* fix CodeQL

* Update CodeQL workflow and Gradle properties

- Enable ignoring disabled targets for Kotlin Native.
- Refine CodeQL build command to specify module targets and rerun tasks.

* Fix auto-merge condition in workflow

- Adjust failure condition to only disable auto-merge for pull requests.

.github/workflows/validate-pr.yml

@@ -1,43 +0,0 @@
-name: Validate PR
-
-on:
-  workflow_dispatch:
-  pull_request:
-    branches: [ main ]
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
-
-jobs:
-  validate-pr:
-    runs-on: macos-latest
-    name: Validate PR
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Set up JDK 21
-        uses: actions/setup-java@v5
-        with:
-          java-version: '21'
-          distribution: 'temurin'
-
-      - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v4
-
-      - name: Clean Build with Gradle
-        run: ./gradlew clean build
-
-      - name: Upload JUnit test results
-        if: always()
-        uses: actions/upload-artifact@v4
-        with:
-          name: junit-results
-          path: '**/build/test-results/test/*.xml'
-
-      - name: Disable Auto-Merge on Fail
-        if: failure()
-        run: gh pr merge --disable-auto "$PR_URL"
-        env:
-          PR_URL: ${{github.event.pull_request.html_url}}
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}