Ignore the Python managed environment error

We've run into https://peps.python.org/pep-0668/, because we install a
bunch of Python packages via apt, and then try to also install the
awscli package via pip, which is not happy about having two sources of
packages.

We've always been doing this, so presumably it's safe to continue
doing so.

.github/workflows/build-rails-buildpack.yml

@@ -33,8 +33,8 @@ jobs:
     - name: prepare
       run: |-
         apk add --no-cache python3 py3-pip
-        pip3 install --upgrade pip
-        pip3 install awscli
+        pip3 install --break-system-packages --upgrade pip
+        pip3 install --break-system-packages awscli
     - name: workaround git security
       run: git config --global --add safe.directory "$GITHUB_WORKSPACE"
     - uses: actions/checkout@v3