Update CI ubuntu version

Author: maksim.konovalov

.github/workflows/main.yml

@@ -13,7 +13,7 @@ jobs:
   all-tests:
     # We could replace it with ubuntu-latest after fixing the bug:
     # https://github.com/tarantool/setup-tarantool/issues/37
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
 
     strategy:
       fail-fast: false