Set the default shell for all run steps in the build workflow

This sets the default shell for any run steps in the build workflow to
mirror our standard shellscript writing practices. In addition to
enabling our standard options it will also print any commands that are
run which should make debugging/troubleshooting more straightforward.

.github/workflows/build.yml

@@ -7,6 +7,14 @@ on:
   repository_dispatch:
     types: [apb]
 
+# Set a default shell for any run steps. The `-Eueo pipefail` sets nounset, errexit,
+# and pipefail. The `-x` will print all commands as they are run. Please see the GitHub
+# Actions documentation for more information:
+# https://docs.github.com/en/actions/using-jobs/setting-default-values-for-jobs
+defaults:
+  run:
+    shell: bash -Eueo pipefail -x {0}
+
 env:
   CURL_CACHE_DIR: ~/.cache/curl
   PIP_CACHE_DIR: ~/.cache/pip