Fixes the terraform module grouping pattern in dependabot.yaml that wasn't working.

Problem

Dependabot was creating individual PRs for each Coder terraform module instead of grouping them together.

Root Cause

The patternregistry.coder.com/coder/*/coder included the registry hostname, but dependabot strips the hostname when naming dependencies. So a module sourced from:

source="registry.coder.com/coder/code-server/coder"

Gets namedcoder/code-server/coder by dependabot (without the hostname).

Fix

Changed the pattern fromregistry.coder.com/coder/*/coder tocoder/*/coder to match the actual dependency names dependabot uses.

This will group updates for modules from bothregistry.coder.com anddev.registry.coder.com since the hostname is stripped in both cases.