ci: fix unsafe directory bug (anuraghazra#2518)

This commit fixes a bug that was introduced due to a upstream change in
the git package. See https://stackoverflow.com/questions/71849415/i-cannot-add-the-parent-directory-to-safe-directory-in-git/71904131#71904131
for more information.

.github/workflows/generate-theme-doc.yml

@@ -23,6 +23,10 @@ jobs:
           node-version: ${{ matrix.node-version }}
           cache: npm
 
+      # Fix the unsafe repo error which was introduced by the CVE-2022-24765 git patches.
+      - name: Fix unsafe repo error
+        run: git config --global --add safe.directory ${{ github.workspace }}
+
       - name: npm install, generate readme
         run: |
           npm ci