www/py-modelsearch: Add py-modelsearch 1.1

Django ModelSearch allows you to index Django models and search them using the
ORM!

It supports PostgreSQL FTS, SQLite FTS5, MySQL FTS, MariaDB FTS, Elasticsearch
(7.x, 8.x, and 9.x), and OpenSearch (2.x and 3.x).

Features:
- Index models in Elasticsearch and OpenSearch and query with the Django ORM
- Reuse existing QuerySets for search, works with Django paginators and
  django-filter
- Also supports PostgreSQL FTS, MySQL FTS, MariaDB FTS and SQLite FTS5
- Autocomplete
- Faceting
- Per-field boosting
- Fuzzy Search
- Phrase search
- Structured queries
- Multi-table inheritance
- Zero-downtime index rebuilding (uses aliases to atomically swap in a new index
  when its ready)

This has been built into Wagtail CMS since 2014 and extracted into a separate
package in March 2025.