Allow PHP 8.5

[dgburns92]

Part of the calendar-api PHP 8.3 → 8.5 hop (BT-278): rexlabs/smokescreen is one of the rexlabs packages whose php constraint stops Composer resolving on 8.5. Shaped like the previous PHP-support bumps in this repo.

• composer.json: php upper bound to <8.6.
• CI matrix gains 8.5 (php:X-cli-alpine, same job as before; checkout action on v4).
• CHANGELOG entry for 2.6.0.

Verification

Ran the workflow's job locally (docker run php:8.5-cli-alpine, composer update --prefer-stable, vendor/bin/phpunit): suite green on PHP 8.5 with no deprecations.

Release as 2.6.0 after merge (gh release create 2.6.0 --target main --generate-notes), which Private Packagist picks up within a minute.

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

This PR extends the package's declared and tested compatibility through PHP 8.5.

• Raises the Composer PHP upper bound from <8.5 to <8.6.
• Adds PHP 8.5 to the existing CI test matrix.
• Documents PHP 8.5 support for release 2.6.0.

Confidence Score: 5/5

The PR appears safe to merge, with the newly declared PHP 8.5 support covered by the existing CI test workflow.

No actionable failures were identified in the compatibility constraint, CI matrix addition, or release documentation.

Important Files Changed

Filename	Overview
composer.json	Expands the supported PHP range to include PHP 8.5.
.github/workflows/pr_test.yml	Adds the PHP 8.5 Alpine CLI image to the existing dependency-resolution and test matrix.
CHANGELOG.md	Records PHP 8.5 support in the planned 2.6.0 release.

_{Reviews (1): Last reviewed commit: "Allow PHP 8.5" | Re-trigger Greptile}