Delete unnecessary Workflow file

.github/workflows/build_debug_apk.yml

@@ -1,28 +0,0 @@
-name: Build debug APK
-
-on:
-  workflow_dispatch:
-  push:
-    branches:
-      - 11-dev
-
-jobs:
-  build-debug-apk:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2.3.4
-        with:
-          submodules: true
-      - name: Set up Java 11
-        uses: actions/setup-java@v1.4.3
-        with:
-          java-version: 11
-      - name: Grant execution permission to Gradle Wrapper
-        run: chmod +x gradlew
-      - name: Build debug APK
-        run: sudo ./gradlew assembleLawnWithQuickstepDebug
-      - name: Upload artifact
-        uses: actions/upload-artifact@v2
-        with:
-          name: Lawnchair
-          path: build/outputs/apk/lawnWithQuickstep/debug/**.apk