Remove redundant ubuntu-latest build

.github/workflows/build_servers_windows.yml

@@ -1,5 +1,5 @@
-name: Build servers with CMake
-# build_servers_cmake.yml
+name: Build servers on Windows
+# build_servers_windows.yml
 
 concurrency:
   group: ${{ github.repository }}-${{ github.workflow }}-${{ github.ref }}
@@ -29,9 +29,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-          # The ubuntu-latest label currently points to ubuntu-22.04.
-          # Available: ubuntu-22.04, ubuntu-20.04
-          os: [ubuntu-latest, windows-latest]
+          os: [windows-latest]
 
     steps:
       - uses: actions/checkout@v2