fix(ci): free temp directory after use

macos machines currently don't clean temp dirs automatically

.github/workflows/concrete_python_release_nightly.yml

@@ -218,7 +218,8 @@ jobs:
 
           export CONCRETE_PYTHON=$(pwd)/frontends/concrete-python
 
-          cd $(mktemp -d)
+          export TEST_TMP_DIR=$(mktemp -d)
+          cd $TEST_TMP_DIR
 
           export PYTHON_VERSION=${{ format('python{0}', matrix.python-version) }}
 
@@ -247,7 +248,7 @@ jobs:
 
           pytest tests -svv -n auto -m "not dataflow"
 
-          deactivate
+          rm -rf $TEST_TMP_DIR
 
   push:
     needs: [linux-x86, macos]

.github/workflows/concrete_python_test_macos.yml

@@ -103,7 +103,8 @@ jobs:
       - name: Test
         run: |
           set -e
-          cd $(mktemp -d)
+          export TEST_TMP_DIR=$(mktemp -d)
+          cd $TEST_TMP_DIR
           
           python3.10 -m venv .testenv
           . .testenv/bin/activate
@@ -121,4 +122,4 @@ jobs:
           cp -R $GITHUB_WORKSPACE/frontends/concrete-python/tests ./tests
           pytest tests -svv -n auto --key-cache "/tmp/KeySetCache" -m "not dataflow"
 
-          deactivate
+          rm -rf $TEST_TMP_DIR