Revert "Github Actions: Try to generate nightly nbms"

This reverts commit a6b530291076da07f83a2d5cd44a7a7bb535b4fa.

.github/workflows/gradle.yml

@@ -1,35 +0,0 @@
-name: Nightly Generation
-
-on:
-  push:
-    branches: [ master ]
-jobs:
-  build:
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v2
-    - name: Set up JDK 11
-      uses: actions/setup-java@v1
-      with:
-        java-version: 11
-    - name: Grant execute permission for gradlew and others.
-      run: chmod +x gradlew *.sh
-      
-    - name: Download the Engine
-      run: ./build_engine.sh
-      
-    - name: Fix the Engine
-      run: ./fix_engine.sh
-      
-    - name: Build
-      run: ./gradlew buildSdk
-      
-    - name: Build Nightly NBMs
-      env:
-        NBM_SIGN_PASS: ${{ secrets.NBM_SIGN_PASS }}
-      # For Stable, use set-spec-version
-      run: ant -Dstorepass="$NBM_SIGN_PASS" set-impl-version suite.nbms unset-impl-version
-  
-    - name: List potential artifacts
-      run: ls -lsh build/ && ls -lsh build/updates