add PIP

Makefile

@@ -15,6 +15,8 @@
 # specific language governing permissions and limitations
 # under the License.
 
+# Use the same Python executable for these commands
+PIP = python -m pip
 POETRY = python -m poetry
 
 help:  ## Display this help
@@ -23,7 +25,7 @@ help:  ## Display this help
 install-poetry:  ## Install poetry if the user has not done that yet.
 	@if ! $(POETRY) --version &> /dev/null; then \
          echo "Poetry could not be found. Installing..."; \
-         python -m pip install poetry==1.8.3; \
+         ${PIP} install poetry==1.8.3; \
      else \
          echo "Poetry is already installed."; \
      fi