Defined static version of windows server

Author: asenyaev

.github/workflows/build_wheels_windows.yml

@@ -21,7 +21,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [windows-latest]
+        os: [windows-2019]
         python-version: ['3.6']
         platform: [x86, x64]
         with_contrib: [0, 1]
@@ -86,7 +86,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [windows-latest]
+        os: [windows-2019]
         python-version: ['3.6', '3.7', '3.8', '3.9', '3.10']
         platform: [x86, x64]
         with_contrib: [0, 1]