[feat] Add `TAURI_SIGNING_PUBLIC_KEY` environment variable

[davidmyersdev]

Describe the problem

Currently, I cannot specify my public signing key from an environment variable, and I have to hard-code it in tauri.conf.json.

Describe the solution you'd like

I would like to set the public signing key via a TAURI_SIGNING_PUBLIC_KEY environment variable.

Alternatives considered

I have considered dynamically generating a custom tauri.conf.json during build, but that seems unnecessarily excessive.

Additional context

No response

[FabianLars]

(not against the feature request) What's the use case for this or rather why can't use the config for this?

I have considered dynamically generating a custom tauri.conf.json during build, but that seems unnecessarily excessive.

There's btw a --config flag that accepts a merge config in the form of a string (or a path but that's what you don't like here)