[brief] Fixing the sourcing of the venv for windows.

[detailed]
- Windows has a different path for the venv files, so we need to handle
  it.

.github/workflows/tests.yml

@@ -40,9 +40,17 @@ jobs:
           path: venv
 
       - name: Install dependencies
+        shell: bash
+        env:
+          RUNNER: ${{ matrix.os }}
         run: |
           python -m venv venv
-          source venv/bin/activate
+          if [[ "$RUNNER" == "windows-latest" ]]; then
+           source venv/Scripts/activate
+          else
+            source venv/bin/activate
+          fi
+
           python -m pip install numpy==1.26.4
           python -m pip install -r requirements/ci.txt
           echo "$VIRTUAL_ENV/bin" >> $GITHUB_PATH