fix: tests are run on the right python version (#243)

Signed-off-by: ThibaultFy <thibault.fouqueray@gmail.com>

.github/workflows/main-check.yml

@@ -3,6 +3,9 @@ on:
   push:
     branches:
       - main
+  pull_request:
+    branches:
+      - main
   workflow_dispatch:
 
 jobs:
@@ -44,11 +47,11 @@ jobs:
           repository: substra/substra
           path: substra
 
-#      - uses: actions/cache@v3.0.8
-#        id: cache
-#        with:
-#          path: ${{ env.pythonLocation }}
-#          key: ${{ runner.os }}-${{ env.pythonLocation }}-pip-${{ hashFiles('substrafl/pyproject.toml') }}-${{ hashFiles  ('substrafl/docs/requirements.txt') }}-${{ hashFiles('substrafl/benchmark/camelyon/requirements.txt') }}
+      - uses: actions/cache@v3.0.8
+        id: cache
+        with:
+          path: ${{ env.pythonLocation }}
+          key: ${{ runner.os }}-${{ env.pythonLocation }}-pip-${{ hashFiles('substrafl/pyproject.toml') }}-${{ hashFiles  ('substrafl/docs/requirements.txt') }}-${{ hashFiles('substrafl/benchmark/camelyon/requirements.txt') }}
 
       - name: Install package
         run: |