Bump phpstan/phpstan to latest to make daily "updated deps" QA run pass again

Problem/Motivation

phpstan/phpstan Released version 1.10.38 (See https://github.com/phpstan/phpstan/releases/tag/1.10.38).

As shown in our daily QA run with updated dependencies here:https://www.drupal.org/pift-ci-job/2780457 it does make it hate DiffEngine a bit more than it already did.

Steps to reproduce

Look at our daily QA run with updated dependencies.

Proposed resolution

- Upgrade phpstan/phpstan to 1.10.38.
- Create a new baseline.
- Bump version of phpstan/phpstan in composer.* to 1.10.38, since the newly created baseline won't pass on any lower version.

$ composer-lock-diff --no-links
+-----------------+---------+---------+
| Dev Changes     | From    | To      |
+-----------------+---------+---------+
| phpstan/phpstan | 1.10.24 | 1.10.38 |
+-----------------+---------+---------+

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet