ci: update docs-builder

[ upstream commit 262d59e ]

Manual update for docs-builder tag, because the related PR's branch was
not opened in the Cilium repository (but from a fork).

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Tam Mach <tam.mach@cilium.io>

.github/workflows/documentation.yaml

@@ -58,7 +58,7 @@ jobs:
         with:
           persist-credentials: false
       - name: Build HTML
-        uses: docker://quay.io/cilium/docs-builder:9eb38bbec80e56a8a498b0cac42456e42cfe7f04@sha256:9936a2f648cb25cad6cf1fe5772ad1a5800d0033eb88b0dce77ad70a083661d9
+        uses: docker://quay.io/cilium/docs-builder:b4742c730ff6b05c0b6b3e3383a264bf706aef5e@sha256:28e22c2f0c747216a5216304855be244f44d8d2752c6f810d0da1918712c5f61
         with:
           entrypoint: ./Documentation/check-build.sh
           args: html