az bicep publish doesn't automatically install Bicep

[johndowns]

Bicep version
run bicep --version via the Bicep CLI, az bicep version via the AZ CLI or via VS code by navigating to the extensions tab and searching for Bicep

Describe the bug
On GitHub Actions, I've noticed that if you run az bicep build without explicitly running az bicep install, the build command installs Bicep automatically.

But, if you run az bicep publish without having run az bicep install, the Azure CLI shows an error saying that Bicep isn't installed.

It'd be nice if the build and publish commands behaved consistently.

To Reproduce
Steps to reproduce the behavior:

Additional context
Add any other context about the problem here.