ci: Remove outdated GitHub workflows

.github/workflows/build.yml

@@ -1,37 +0,0 @@
-name: Build
-
-on:
-  pull_request:
-    branches:
-      - main
-
-concurrency:
-  cancel-in-progress: true
-  group: ${{ github.workflow }}-${{ github.ref }}
-
-jobs:
-  build:
-    runs-on: ubuntu-24.04
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - uses: actions/setup-java@v4
-        with:
-          distribution: 'temurin'
-          java-version: 21
-      - name: Update environment variables based on PR labels
-        id: pr-env
-        uses: actions/github-script@v7
-        with:
-          script: |
-            const labels = context.payload.pull_request.labels.map(label => label.name);
-            console.log('PR labels:', labels);
-            const springDebug = labels.includes('pr-debug');
-            return { SPRING_DEBUG: '' + springDebug };
-          result-encoding: json
-      - uses: gradle/actions/setup-gradle@v4
-      - name: Build gradle project
-        run: ./gradlew build
-        env:
-          ORG_GRADLE_PROJECT_SPRING_DEBUG: ${{ fromJSON(steps.pr-env.outputs.result).SPRING_DEBUG }}

.github/workflows/formatting.yml

@@ -1,28 +0,0 @@
-name: Check formatting
-
-on:
-  pull_request:
-    branches:
-      - main
-
-concurrency:
-  cancel-in-progress: true
-  group: ${{ github.workflow }}-${{ github.ref }}
-
-jobs:
-  check-formatting:
-    runs-on: ubuntu-24.04
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - uses: actions/setup-java@v4
-        with:
-          distribution: 'temurin'
-          java-version: 21
-      - uses: gradle/actions/setup-gradle@v4
-      - uses: actions/setup-node@v4
-        with:
-          node-version: 20
-      - name: Run formatting check
-        run: ./gradlew spotlessCheck