Revert "chore: Use Python 3.12 to build docs"

This reverts commit cae3359.

Author: effigies

.github/workflows/docs-build-pr.yml

@@ -15,10 +15,6 @@ jobs:
       with:
         fetch-depth: 0
 
-    - uses: actions/setup-python@v5
-      with:
-        python-version: 3.12
-
     - name: Determine current branch/tag name
       run: |
         if [[ "$GITHUB_REF" == refs/pull/* ]]; then

.github/workflows/docs-build-update.yml

@@ -16,10 +16,6 @@ jobs:
         ssh-key: "${{ secrets.NIPREPS_DEPLOY }}"
         fetch-depth: 0
 
-    - uses: actions/setup-python@v5
-      with:
-        python-version: 3.12
-
     - name: Determine current branch/tag name & set-up git author
       run: |
         if [[ "$GITHUB_REF" == refs/tags/* ]]; then