build: further tweak tohandle GHA for releases (?)

Wouldn't it be nice if this were a typed API instead of some string-based
nonsense that looks like it just gets flattened into optional-all-the-way
hash map shenanigans or something? :sigh:

.github/workflows/CI and CD.yml

···
     name: Create and upload release
     needs: [check]
     if: ${{
-      (github.event.push.commits[0].author.username == 'chriskrycho' && github.ref_name == 'main')
+      (github.event.commits[0].author.username == 'chriskrycho' && github.ref_name == 'main')
       || github.event_name == 'workflow_dispatch'
       }}
     permissions: