[EN-8798] [PythonAPI] Lock the Сython version

.github/workflows/test_on_pr.yml

@@ -29,10 +29,8 @@ jobs:
     - name: Set poetry env
       run: |
         pip install --upgrade pip
-        pip install taskipy cython toml
-        poetry install --only main
-        task build -f sdist
-        pip uninstall --yes taskipy cython
+        poetry install
+        poetry build -f sdist
       shell: bash
 
     - name: Install package artifact
@@ -65,7 +63,6 @@ jobs:
     - name: Set poetry env
       run: |
         pip install --upgrade pip
-        pip install taskipy cython toml
         poetry install
       shell: bash
 

pyproject.toml

@@ -61,7 +61,7 @@ post_build = 'task clear'
 post_test = 'task clear'
 
 [build-system]
-requires = ['poetry_core>=1.0.0', 'setuptools>=57.4.0', 'cython', 'toml>=0.10.2']
+requires = ['poetry_core>=1.0.0', 'setuptools>=57.4.0', 'cython==0.29.37', 'toml>=0.10.2']
 build-backend = 'poetry.core.masonry.api'
 
 [build.native-dependencies]