add lint opt deps; add cython-lint check in CI

.github/workflows/main.yml

@@ -32,20 +32,23 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install black 'pylint<3' 'isort[colors]<6'
-          pip install -v --editable .
+          pip install -v --editable .[lint]
 
       - name: black check
         run: |
           python -m black --check --diff --color .
 
+      - name: isort check
+        run: |
+          python -m isort --check --diff --color .
+
       - name: pylint check
         run: |
           python -m pylint src/gstools/
 
-      - name: isort check
+      - name: cython-lint check
         run: |
-          python -m isort --check --diff --color .
+          cython-lint src/gstools/
 
   build_wheels:
     name: wheels for ${{ matrix.cfg.os }} / ${{ matrix.cfg.arch }}

pyproject.toml

@@ -72,6 +72,12 @@ plotting = [
 ]
 rust = ["gstools_core>=0.2.0,<1"]
 test = ["pytest-cov>=3"]
+lint = [
+    "black",
+    "pylint<3",
+    "isort[colors]<6",
+    "cython-lint",
+]
 
 [project.urls]
 Changelog = "https://github.com/GeoStat-Framework/GSTools/blob/main/CHANGELOG.md"