Add GitHub Actions workflow

Thank you to LostLuma for letting me copy this
from Dynamic FPS

Co-authored-by: LostLuma <[email protected]>

.github/workflows/build.yaml

@@ -0,0 +1,42 @@
+name: build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        java: [
+          21,
+        ]
+        os: [
+          ubuntu-24.04,
+          windows-2022,
+        ]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: checkout repository
+        uses: actions/checkout@v4
+      - name: validate gradle wrapper
+        uses: gradle/actions/wrapper-validation@v3
+      - name: setup jdk ${{ matrix.java }}
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: ${{ matrix.java }}
+      - name: make gradle wrapper executable
+        if: ${{ runner.os != 'Windows' }}
+        run: chmod +x ./gradlew
+      - name: setup gradle
+        uses: gradle/actions/setup-gradle@v3
+        with:
+          cache-read-only: ${{ github.ref != 'refs/heads/meow' }}
+      - name: build
+        run: ./gradlew build --warning-mode=all
+      - name: capture build artifacts
+        if: ${{ runner.os == 'Linux' && matrix.java == '21' }} # Upload artifacts from one job, ignore the rest
+        uses: actions/upload-artifact@v4
+        with:
+          name: kit-tunes-artifacts
+          path: build/libs
+          if-no-files-found: error