ci: drop cartridge 1.2.0

Cartridge 1.2.0 was deprecated a long time ago after 2.x release. Now CI
actually doesn't run with cartridge 1.2.0: after [1] we run tests with
migrations, which depends on `cartridge >= 2.0.1-1, <3.0.0`, installing
latest cartridge 2.x over expected 1.2.0.

1. 4409775

Author: DifferentialOrange

.github/workflows/test_on_push.yaml

@@ -30,8 +30,6 @@ jobs:
           - tarantool-version: "2.10"
             metrics-version: "0.10.0"
             cartridge-version: "2.7.8"
-          - tarantool-version: "1.10"
-            cartridge-version: "1.2.0"
           - tarantool-version: "2.10"
             coveralls: true
             metrics-version: "0.16.0"