fix: type annotation in test helper

Author: mgrabovsky

test/test_solvers.py

@@ -5,13 +5,17 @@
 @author: sid
 """
 
+import contextlib
 from pathlib import Path
 from unittest.mock import MagicMock
 
 import numpy as np
 import pytest
 from test_io import model  # noqa: F401
 
+with contextlib.suppress(ModuleNotFoundError):
+    import mosek
+
 from linopy import GREATER_EQUAL, Model, solvers
 from linopy.constants import Result, Solution, Status
 from linopy.constraints import CSRConstraint
@@ -361,7 +365,9 @@ def test_knitro_solver_no_log(tmp_path: Path) -> None:
 @pytest.mark.skipif(
     "gurobi" not in set(solvers.licensed_solvers), reason="Gurobi is not installed"
 )
-def test_gurobi_environment_with_dict(model: Model, tmp_path: Path) -> None:  # noqa: F811
+def test_gurobi_environment_with_dict(
+    model: Model, tmp_path: Path
+) -> None:  # noqa: F811
     gurobi = solvers.Gurobi()
 
     mps_file = tmp_path / "problem.mps"
@@ -387,7 +393,9 @@ def test_gurobi_environment_with_dict(model: Model, tmp_path: Path) -> None:  #
 @pytest.mark.skipif(
     "gurobi" not in set(solvers.licensed_solvers), reason="Gurobi is not installed"
 )
-def test_gurobi_environment_with_gurobi_env(model: Model, tmp_path: Path) -> None:  # noqa: F811
+def test_gurobi_environment_with_gurobi_env(
+    model: Model, tmp_path: Path
+) -> None:  # noqa: F811
     import gurobipy as gp
 
     gurobi = solvers.Gurobi()
@@ -471,7 +479,10 @@ def test_xpress_gpu_feature_reflects_installed_version() -> None:
 
 
 def _make_mosek_task_mock(
-    *, bas_solsta=None, itr_solsta=None, itg_solsta=None
+    *,
+    bas_solsta: "mosek.solsta | None" = None,
+    itr_solsta: "mosek.solsta | None" = None,
+    itg_solsta: "mosek.solsta | None" = None,
 ) -> MagicMock:
     """Build a ``mosek.Task`` mock with controlled per-soltype statuses."""
     mosek = pytest.importorskip("mosek", reason="Mosek is not installed")