Dropped PHP 7.3 support, update dependency laminas/laminas-coding-standard to ^2.4.0, removed prophecy mocks

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change
laminas/laminas-coding-standard (source)	require-dev	minor	~2.3.0 -> ~2.4.0

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

♻ Rebasing: Renovate will not automatically rebase this PR, because other commits have been found.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

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• [ ] If you want to rebase/retry this PR, click this checkbox. ⚠ Warning: custom changes will be lost.

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[renovate[bot]]

⚠ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

♻ Renovate will retry this branch, including artifacts, only when one of the following happens:

• any of the package files in this branch needs updating, or
• the branch becomes conflicted, or
• you click the rebase/retry checkbox if found above, or
• you rename this PR's title to start with "rebase!" to trigger it manually

The artifact failure details are included below:

File name: composer.lock

Command failed: docker run --rm --name=renovate_php --label=renovate_child -v "/mnt/renovate/gh/laminas/laminas-diactoros":"/mnt/renovate/gh/laminas/laminas-diactoros" -v "/tmp/renovate-cache":"/tmp/renovate-cache" -e COMPOSER_CACHE_DIR -e COMPOSER_AUTH -e BUILDPACK_CACHE_DIR -w "/mnt/renovate/gh/laminas/laminas-diactoros" docker.io/renovate/php:latest bash -l -c "install-tool composer 2.4.1 && composer update laminas/laminas-coding-standard --with-dependencies --ignore-platform-req='ext-*' --ignore-platform-req='lib-*' --no-ansi --no-interaction --no-scripts --no-autoloader --no-plugins"
Loading composer repositories with package information
Info from https://repo.packagist.org: #StandWithUkraine
Updating dependencies
Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Root composer.json requires laminas/laminas-coding-standard ~2.4.0 -> satisfiable by laminas/laminas-coding-standard[2.4.0].
    - laminas/laminas-coding-standard 2.4.0 requires php ^7.4 || ^8.0 -> your php version (7.3.99; overridden via config.platform, actual: 7.4.30) does not satisfy that requirement.

Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.