Bump postgres version in gh workflows (#4254)

PostgreSQL v10 and v11 already reached there EOL: https://www.postgresql.org/support/versioning/

Author: johha

.github/workflows/unit_tests.yml

@@ -43,7 +43,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        image: ["postgres:10", "postgres:11", "postgres:16"]
+        image: ["postgres:13", "postgres:15", "postgres:16"]
     services:
       postgres:
         image: ${{ matrix.image }}

.github/workflows/unit_tests_backwards_compatibility.yml

@@ -33,7 +33,7 @@ jobs:
       fail-fast: false
       max-parallel: 3
       matrix:
-        image: ["postgres:10", "postgres:11", "postgres:16"]
+        image: ["postgres:13", "postgres:15", "postgres:16"]
     services:
       postgres:
         image: ${{ matrix.image }}