PHP: Update to Debian 13 (Trixie) based images & remove IMAP extension

[jakubboucek]

This PR upgrades PHP images to Debian 13 (Trixie) linux, see more info at: docker-library/php#1596

Remove IMAP extension

Extension imap is marked as Deprecated and now is incompatible with Trixie (docker-library/php#1610). It was decided to remove him from images. Extension will be available only in older images up to: 8.3.24, 8.2.28, and 8.1.32, and remains in legacy images (8.0 and older).

BC Breaks

• Removed imap extension – see reasons above

[Copilot]

Pull Request Overview

This PR upgrades PHP Docker images from Debian 12 (Bookworm) to Debian 13 (Trixie) and removes the deprecated IMAP extension due to compatibility issues.

• Updates all PHP Docker images (8.1-8.5) to use Debian 13 (Trixie) base images
• Removes IMAP extension support which is incompatible with the new Debian version
• Updates system dependencies to their Trixie equivalents

Reviewed Changes

Copilot reviewed 24 out of 24 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
php/sources.list-trixie	Adds Debian 13 package sources configuration
php/sources.list-bookworm	Removes Debian 12 package sources configuration
php/build-php-*.sh	Updates Docker image references from bookworm to trixie
php/Dockerfile-*	Updates base images, dependency versions, and removes IMAP configuration
check-pulls.sh	Updates image references in CI checks
README.md	Documents IMAP extension removal and compatibility notes

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