docs(docs-infra): prevent auto-linking of snippet in guide (#33877)

By adding the `bash` language to the code snippet it will no
longer be auto-linked, which was causing a false positive link
to be rendered.

Fixes #33859

PR Close #33877

aio/content/guide/updating-to-version-9.md

@@ -6,7 +6,7 @@ This guide contains everything you need to know about updating to the next Angul
 
 If your application uses the CLI, you can update to version 9 automatically with the help of the `ng update` script:
 
-```
+```sh
 ng update @angular/core@8 @angular/cli@8
 git add .
 git commit --all -m "build: update Angular packages to latest 8.x version"