Limit concurrent requests more

Strongly limit concurrent requests to avoid rate limiting errors (429)

Author: seaxwi

.github/workflows/check-urls.yml

@@ -15,7 +15,7 @@ jobs:
         id: lychee
         uses: lycheeverse/lychee-action@v1
         with:
-          args: --no-progress --verbose --require-https 'content/*/*/*.md' --max-retries 0 --max-concurrency 32
+          args: --no-progress --verbose --require-https 'content/*/*/*.md' --max-retries 0 --max-concurrency 1
           fail: true
         env:
           CLICOLOR_FORCE: 1