Replaced `django-prometheus` with the default Django components, including model mixins, database backends, and cache configuration. This change simplifies monitoring setup by removing unnecessary dependencies, reducing overhead, and improving compatibility.
**Details:**
- Removed Prometheus metrics endpoints and middleware.
- Updated database, cache, and model configurations to remove `django-prometheus`.
- Adjusted WSGI settings to integrate OpenTelemetry instrumentation instead of Prometheus.
- Updated dependency files and migration schemas accordingly.
Updated `product.slug` to use `TweakedAutoSlugField` for improved functionality, allowing unicode, overwrite capabilities, and enhanced population logic. Adjusted the corresponding migration script to ensure seamless database schema updates.
Also marked `brand.categories` as deprecated.
