ci: try passing +nightly in alias for Rustfmt job

Author: obycode

.github/workflows/ci.yml

@@ -47,6 +47,8 @@ jobs:
       - name: Rustfmt
         id: rustfmt
         uses: stacks-network/actions/rustfmt@main
+        with:
+          alias: "+nightly fmt"
 
   ######################################################################################
   ## Check if the branch that this workflow is being run against is a release branch