Upgrade virtualenv's builtin tool wheels

virtualenv embeds versions of pip/wheel and setuptools that in
combination appears to break build of the package
`crispy-forms-foundation`, causing the resulting wheel/package to *not*
contain its package data files - specifically the Django templates that
are necessary for the package to even work.

.github/workflows/build-and-test.yml

@@ -50,6 +50,13 @@ jobs:
           python -m pip install --upgrade pip setuptools wheel tox tox-gh-actions coverage virtualenv snmpsim
           sudo apt-get install -y nbtscan
 
+      # virtualenv seems to currently be embedding a broken version of
+      # setuptools (2022-03-31).  this ensures these embedded wheels are always
+      # up to date, but can potentially be removed again down the road.
+      - name: "Upgrade embedded virtualenv wheels"
+        run: |
+          virtualenv --upgrade-embed-wheel
+
       - name: "Install libraries needed to build external dependencies"
         run: |
           set -xe