Work around cloudflare R2 / aws client incompatability (#29086)

Hopefully...

https://www.cloudflarestatus.com/incidents/t5nrjmpxc1cj

Author: dbkr

.github/workflows/build_develop.yml

@@ -116,6 +116,8 @@ jobs:
               env:
                   AWS_ACCESS_KEY_ID: ${{ secrets.CF_R2_ACCESS_KEY_ID }}
                   AWS_SECRET_ACCESS_KEY: ${{ secrets.CF_R2_TOKEN }}
+                  # Workaround for https://www.cloudflarestatus.com/incidents/t5nrjmpxc1cj
+                  AWS_REQUEST_CHECKSUM_CALCULATION: when_required
 
             - name: Deploy to Cloudflare Pages
               id: cfp