Handle new yarn 4 requirement

Author: rfay

install.yaml

@@ -26,7 +26,7 @@ post_install_actions:
   - cp core-dev/gitignore ../.gitignore
   - mkdir -p ../test_output
   - chmod +w ../test_output
-  - cd ../ && ddev exec yarn --cwd="core"
+  - cd ../core && ddev yarn
 
 removal_actions:
   - rm core/phpunit.xml

web-build/Dockerfile

@@ -1,2 +1,6 @@
 #ddev-generated
-RUN sudo apt-get update && sudo apt-get install chromium-driver -y
+# Note that the chromium-driver install could be moved to webimage_extra_packages
+RUN sudo apt-get update && sudo apt-get install chromium-driver -y
+# Depending on the outcome of https://github.com/ddev/ddev/pull/5988
+# this may not be necessary in DDEV v1.23+
+RUN corepack enable