[meta] rm the configureZshAsDefaultShell [skip ci]

don't need this anymore.

.devcontainer.json

@@ -23,10 +23,7 @@
         }
     },
     "features": {
-        // zsh as default shell for my dotfiles to work
-        "ghcr.io/devcontainers/features/common-utils:2": {
-            "configureZshAsDefaultShell": true
-        },
+        "ghcr.io/devcontainers/features/common-utils:2": {},
         "ghcr.io/devcontainers/features/docker-in-docker:2": {},
         "ghcr.io/devcontainers/features/github-cli:1": {},
         "ghcr.io/joshuanianji/devcontainer-features/github-cli-persistence:1": {}