Update actions

Author: vadyushkins

.github/workflows/deploy_docs.yml

@@ -8,7 +8,7 @@ jobs:
   documentation:
     # Do not attempt to deploy documentation on forks
     if: github.repository_owner == 'JetBrains-Research'
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-latest
     strategy:
       matrix:
         python-version: [ 3.8 ]

.github/workflows/tests.yml

@@ -8,14 +8,8 @@ jobs:
     strategy:
       matrix:
         os: [
-            ubuntu-16.04,
-            ubuntu-18.04,
-            ubuntu-20.04,
             ubuntu-latest,
-            macos-10.15,
             macos-latest,
-            windows-2016,
-            windows-2019,
             windows-latest,
         ]
         python-version: [ 3.7, 3.8, 3.9 ]
@@ -40,15 +34,8 @@ jobs:
 
   # Only supported on linux platform
   docker:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        os: [
-            ubuntu-16.04,
-            ubuntu-18.04,
-            ubuntu-20.04,
-            ubuntu-latest,
-        ]
+    runs-on: ubuntu-latest
+
     steps:
       - uses: actions/checkout@v2