Allow installing canvas 1.9.*

Problem/Motivation

Canvas 1.9.0 was released on 29 July 2026. canvas_extjs works fine against it, but composer.json still caps the dependency below 1.9, so the module cannot be installed on a 1.9 site.

Steps to reproduce

On a Drupal 11.3+ site:

composer require 'drupal/canvas:1.9.0'
composer require 'drupal/canvas_extjs:^1.2'

The second command fails to resolve:

drupal/canvas_extjs requires drupal/canvas >=1.5 <1.9
  -> found drupal/canvas[1.5.0, ..., 1.8.0] but it conflicts with
     your root composer.json require (1.9.0).

Proposed resolution

Raise the upper bound from 1.9 to 1.10 so the constraint becomes >=1.5 <1.10. This admits all 1.9.x releases while still excluding 1.10 until it has been tested. No code changes are needed.

Remaining tasks

User interface changes

API changes

Data model changes