CI: Don't run poetry update

This causes `poetry` to regenerate the `poetry.lock` file with newer versions
of dependencies, which defeats the point of checking in the lock file in the
first place.

.github/workflows/ci.yml

@@ -373,7 +373,6 @@ jobs:
           - name: Install on MacOS
             test: |
               cd saw-remote-api/python/
-              poetry update
               poetry install
               poetry run mypy --install-types --non-interactive saw_client/ || true
               poetry run mypy --install-types --non-interactive saw_client/

saw-remote-api/scripts/run_rpc_tests.sh

@@ -13,7 +13,6 @@ function run_test {
 }
 
 echo "Setting up python environment for remote server clients..."
-poetry update
 poetry install
 
 echo "Typechecking code with mypy..."

saw-remote-api/scripts/test_docker.sh

@@ -38,7 +38,6 @@ sleep 5 # let the server catch its breath and be ready for requests
 
 
   echo "Setting up python environment for remote server clients...";
-  poetry update;
   poetry install;
 
   export SAW_SERVER_URL="http://localhost:8080/";