ci: remove windows

The FDB community is officially discontinuing the Windows build (see
apple/foundationdb#5135 for more info). We cannot download msi packages
as they were removed from official sites.

As the `windows-latest` is mandatory for any PR, this commit is removing
the `windows-latest` from Github actions. We may add it back later to
use community build.

Author: PierreZ

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        os: [ubuntu-latest, macos-latest, windows-latest]
+        os: [ubuntu-latest, macos-latest]
         toolchain: ["1.40.0", "stable"]
 
     runs-on: ${{ matrix.os }}
@@ -24,13 +24,6 @@ jobs:
       - name: Install FoundationDB
         uses: Clikengo/foundationdb-actions-install@v1
 
-      - name: Install Clang
-        if: matrix.os == 'windows-latest'
-        run: |
-          curl -fsSL -o LLVM9.exe https://releases.llvm.org/9.0.0/LLVM-9.0.0-win64.exe
-          7z x LLVM9.exe -y -o"C:/Program Files/LLVM"
-          echo "LIBCLANG_PATH=C:/Program Files/LLVM/bin" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
-
       - name: Install Rust toolchain
         uses: actions-rs/toolchain@v1
         with: