Remove broken PR build workflow for now

.github/workflows/pr_build_check.yml

@@ -1,18 +0,0 @@
-name: Pull request build check
-on: [pull_request]
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Clone repo
-        uses: actions/checkout@v2
-      - name: Set up JDK 1.8
-        uses: actions/setup-java@v1
-        with:
-          java-version: 1.8
-      - name: Install NDK
-        run: sudo ${ANDROID_HOME}/tools/bin/sdkmanager --install "ndk;21.3.6528147"
-      - name: Build project
-        run: ./gradlew assembleDebug