Use new config file name wrangler.gdk.toml for the HTTP Router

What does this merge request do and why?

GDK uses wrangler.gdk.toml for the HTTP Router.

Why ?

TLDR Version: GDK generated files for local config files are usually .gitignored in our projects.

There was some context here: gitlab-org/cells/http-router!217 (comment 2082950702)

GDK generates wrangler.toml file when running gdk reconfigure. Which might cause accidental change of this file, because it's not .gitignored.

At GitLab, for our projects we usually add the local config file to .gitignore. See here for example: https://gitlab.com/gitlab-org/gitlab/-/blob/master/.gitignore?ref_type=heads#L35-39

But for the HTTP Router, this wrangler.toml file is used to hold config for the pre and staging environments. And it was suggested in this MR to use a different file for GDK.

If this gets approved and merged, I will follow up on this by adding wrangler.gdk.toml to the .gitignore of the HTTP Router, to prevent it from showing up in git diff or accidentally committing its changes, as these usually belong to the local environment.

How to set up and validate locally

1. Check out this branch
2. Run gdk reconfigure
3. See a change in the Procfile to use the new config file name
4. Run gdk restart
5. Run gdk open
6. See that it works

Impacted categories

The following categories relate to this merge request:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.

Merge request checklist

• This change is backward compatible. If not, please include steps to communicate to our users.
• Tests added for new functionality. If not, please raise an issue to follow-up.
• Documentation added/updated, if needed.
• Announcement added, if change is notable.
• gdk doctor test added, if needed.
• Add the ~highlight label if this MR should be included in the CHANGELOG.md.