ci: Create forgejo workflows

.forgejo/workflows/build.yml

@@ -0,0 +1,27 @@
+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: code.forgejo.org/actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: github.com/actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: 21
+      - uses: github.com/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 }}

.forgejo/workflows/formatting.yml

@@ -0,0 +1,28 @@
+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: code.forgejo.org/actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: github.com/actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: 21
+      - uses: github.com/gradle/actions/setup-gradle@v4
+      - uses: code.forgejo.org/actions/setup-node@v4
+        with:
+          node-version: 20
+      - name: Run formatting check
+        run: ./gradlew spotlessCheck