Add missing dependency

The query pack has suites that rely on the `codeql/suite-helpers` pack, but doesn't include it as a dependency.
This will cause error when resolving suites referring the Actions query pack.

Author: rvermeulen

actions/ql/src/qlpack.yml

@@ -8,3 +8,4 @@ extractor: actions
 defaultSuiteFile: codeql-suites/actions-code-scanning.qls
 dependencies:
   codeql/actions-all: ${workspace}
+  codeql/suite-helpers: ${workspace}