do not check unleash on every PR, only master and tags (#5054)

* do not check unleash on every PR, only master and tags

* move scripts folder

* add signed-tag check to CI

* remove publish-to-crates-io dependencies

Co-authored-by: s3krit <pugh@s3kr.it>

substrate/.maintain/gitlab/check_signed.sh

@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+
+# shellcheck source=lib.sh
+source "$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )/lib.sh"
+
+version="$CI_COMMIT_TAG"
+
+echo '[+] Checking tag has been signed'
+check_tag "paritytech/substrate" "$version"
+case $? in
+  0) echo '[+] Tag found and has been signed'; exit 0
+    ;;
+  1) echo '[!] Tag found but has not been signed. Aborting release.'; exit 1
+    ;;
+  2) echo '[!] Tag not found. Aborting release.'; exit 1
+esac