github actions delete "C/C++ CI"

- this was the original github actions test build that's been superseded by many others

.github/workflows/ccpp.yml

@@ -1,26 +0,0 @@
-name: C/C++ CI
-
-on:
-  push:
-    branches:
-    - 'master'
-  pull_request:
-    branches:
-    - '*'
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        ubuntu_release: [
-          bionic,
-          focal
-          ]
-    container: px4io/px4-dev-base-${{ matrix.ubuntu_release }}:2020-04-01
-    steps:
-    - uses: actions/checkout@v1
-      with:
-        token: ${{ secrets.ACCESS_TOKEN }}
-    - name: make
-      run: make