Delete the unofficial GitHub actions tests.

We do not look at these.

Close #4509

PiperOrigin-RevId: 621511191
Change-Id: Icbd3fe0a18444e0888bbec61345c6a957d8899d6

.github/workflows/gtest-ci.yml

@@ -1,43 +0,0 @@
-name: ci
-
-on:
-  push:
-  pull_request:
-
-env:
-  BAZEL_CXXOPTS: -std=c++14
-
-jobs:
-  Linux:
-    runs-on: ubuntu-latest
-    steps:
-
-    - uses: actions/checkout@v3
-      with:
-        fetch-depth: 0
-
-    - name: Tests
-      run: bazel test --cxxopt=-std=c++14 --features=external_include_paths --test_output=errors ...
-
-  macOS:
-    runs-on: macos-latest
-    steps:
-
-    - uses: actions/checkout@v3
-      with:
-        fetch-depth: 0
-
-    - name: Tests
-      run:  bazel test --cxxopt=-std=c++14 --features=external_include_paths --test_output=errors ...
-
-
-  Windows:
-    runs-on: windows-latest
-    steps:
-
-    - uses: actions/checkout@v3
-      with:
-        fetch-depth: 0
-
-    - name: Tests
-      run: bazel test --cxxopt=/std:c++14 --features=external_include_paths --test_output=errors ...