fix: Syntax error: redirection unexpected

the `sh` provided by CI uses different shell than bash, so '<<<' used in
/entrypoint.sh:35 did not work - this should fix it

.github/actions/update-on-new-ipfs-tag/entrypoint.sh

@@ -1,4 +1,4 @@
-#!/usr/bin/env sh
+#!/usr/bin/env bash
 set -eu
 
 API_FILE=`pwd`/docs/reference/http/api.md