Tests: centralized test enabling logic, better parallelization in CI

Removing some heavy toolchains from windows/macos run (they will be tested only in the job based off the maximal docker image)

test/solidlsp/elixir/test_elixir_basic.py

@@ -12,13 +12,12 @@ import pytest
 from solidlsp import SolidLanguageServer
 from solidlsp.ls_config import Language
 from solidlsp.ls_types import SymbolKind
+from test.conftest import language_tests_enabled
 from test.solidlsp.conftest import format_symbol_for_assert, has_malformed_name, request_all_symbols
 from test.solidlsp.util.diagnostics import assert_file_diagnostics
 
-from . import EXPERT_UNAVAILABLE, EXPERT_UNAVAILABLE_REASON
-
 # These marks will be applied to all tests in this module
-pytestmark = [pytest.mark.elixir, pytest.mark.skipif(EXPERT_UNAVAILABLE, reason=f"Next LS not available: {EXPERT_UNAVAILABLE_REASON}")]
+pytestmark = [pytest.mark.elixir, pytest.mark.skipif(not language_tests_enabled(Language.ELIXIR), reason="Elixir tests are disabled")]
 
 
 class TestElixirBasic: