fix: remove deprecated windows-2016/vs-2017 action runner from build matrix (#3484)

* fix(action): bump Windows 2016 runner to 2019

* fix(action): remove explicit win 2016/2019 runner config

Co-authored-by: Paweł <zneix@zneix.eu>

.github/workflows/build.yml

@@ -16,16 +16,7 @@ jobs:
         qt-version: [5.15.2, 5.12.10]
         build-system: [qmake, cmake]
         pch: [true]
-        exclude:
-          - os: windows-latest
-            qt-version: 5.12.10
-            build-system: cmake
-            pch: true
         include:
-          - os: windows-2016
-            qt-version: 5.12.10
-            build-system: cmake
-            pch: true
           - os: ubuntu-latest
             qt-version: 5.15.2
             build-system: cmake
@@ -39,12 +30,6 @@ jobs:
             echo "vs_version=2019" >> $GITHUB_ENV
         shell: bash
 
-      - name: Set environment variables for windows-2016
-        if: matrix.os == 'windows-2016'
-        run: |
-            echo "vs_version=2017" >> $GITHUB_ENV
-        shell: bash
-
       - uses: actions/checkout@v2.4.0
         with:
           submodules: true