remove coverage and old ci scripts

.github/workflows/coverage.yml

@@ -1,16 +0,0 @@
-name: coverage
-
-on: [push, pull_request]
-
-jobs:
-  build:
-    runs-on: macos-11
-    name: "coverage"
-    steps:
-    - uses: actions/checkout@v2
-      with:
-        submodules: recursive
-    - name: Install lcov by Homebrew
-      run: brew install lcov
-    - name: Build && Test && Upload
-      run: .ci/build_coverage.sh