Revert "ci: parallelize the mdbook build <language> process"

This reverts commit 9ad2542.

Author: michael-kerscher

.github/workflows/build.sh

@@ -15,19 +15,6 @@ set -Eeuo pipefail
 book_lang=${1:?"Usage: $0 <book-lang> <dest-dir>"}
 dest_dir=${2:?"Usage: $0 <book-lang> <dest-dir>"}
 
-# ensure source dir exists
-mkdir -p source
-# clean previous build artifacts
-SOURCE_DIR="source/${book_lang}"
-rm -rf "$SOURCE_DIR"
-mkdir "$SOURCE_DIR"
-
-# clone the current state into the source directory
-git clone . "$SOURCE_DIR"
-
-# now work from that new directory as the base directory
-cd "$SOURCE_DIR"
-
 if [ "$book_lang" = "en" ]; then
     echo "::group::Building English course"
 else

.github/workflows/publish.yml

@@ -41,10 +41,12 @@ jobs:
         run: .github/workflows/build.sh en book
 
       - name: Build all translations
-        # note: build.sh here uses the given book path relative to source/{language}
         run: |
-          parallel -i .github/workflows/build.sh {} book/{} -- ${{ env.LANGUAGES }}
-          parallel -i mv source/{}/book/{}/html book/html/{} -- ${{ env.LANGUAGES }}
+          for po_lang in ${{ env.LANGUAGES }}; do
+              .github/workflows/build.sh $po_lang book/$po_lang
+              mv book/$po_lang/html book/html/$po_lang
+          done
+
       - name: Build translation report
         run: i18n-report report book/html/translation-report.html po/*.po