gha: update docs-upstream to pin workflows by sha

This workflow was updated in 56e2dba
but it looks to have pinned to a version before the workflows were
pinned; https://github.com/docker/docs/blob/464a44a6e72b37cf1755968477e242a5e5f6ef7d/.github/workflows/validate-upstream.yml

This patch updates the workflow to a version that uses pinned actions;
https://github.com/docker/docs/blob/00aefd5eae73898c4d3bcd7a6fe95a039293706b/.github/workflows/validate-upstream.yml

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah

.github/workflows/docs-upstream.yml

@@ -44,7 +44,7 @@ jobs:
           retention-days: 1
 
   validate:
-    uses: docker/docs/.github/workflows/validate-upstream.yml@464a44a6e72b37cf1755968477e242a5e5f6ef7d # main 2026-03-24
+    uses: docker/docs/.github/workflows/validate-upstream.yml@00aefd5eae73898c4d3bcd7a6fe95a039293706b # main 2026-03-24
     needs:
       - docs-yaml
     with: