Allow PHP 8.4 to be used, raise minimum PHP requirement to 8.1

Allow PHP 8.4 to be used (#25)

Also, include it in the test matrix. At the same time, time to let go of
old versions.

Reduces the log level for `Kept object with id...` messages to `debug` (#22)

What's Changed

• Reduce log level for events that make most of the log volume with least of newsworthiness by @mpdude in #22

Full Changelog: 3.6.1...3.7.0

Allow newer versions of psr/log to be used

What's Changed

• Aktualisiere PHP-CS-Fixer auf v3.62.0 by @mpdude in #18
• Nutze Docker-Image von friendsofphp/php-cs-fixer by @mpdude in #19
• Allow newer versions of psr/log to be used by @mpdude in #20
• Update dependencies by @mpdude in #21

Full Changelog: 3.6.0...3.6.1

Allow the usage of PHP 8.3

3.6.0

Allow the usage of PHP 8.3 (#17)

Adds type hints to support static analysis with Psalm

Add type hints for static linting with Psalm (#10)

This PR adds type hints and docblocks to support static analysis of your custom mapper classes with Psalm.

Most notably, `SourceAdapter`, `DestinationAdapter` and `Mapper` implementations can make use of templated types in Psalm, which is a great help due to the generic (`object` based) approach in this package.

The types are:

* `Ts` type returned by the `SourceAdapter`
* `Tr` type returned by `DestinationAdapter::getObjectsOrderedById()`, `r` for "reading"
* `Tw` type used by the `DestinationAdapter` when writing back to the destination system.

Adds the "unmappble" result type

Add a new "unmappable" result type

This can be used if a source object should be treated as if it does
not exists (don't insert/delete when present). In some cases, this
cannot be detected unless the mapping is attempted.

Normally, such objects should not be returned from the SourceAdapter
in the first place.

Adds check to catch IDs being out of order

3.3.0

Bump requirements to PHP 7.1

Adds hooks for memory/GC optimization

3.2.0

Fix wrong version number in CHANGELOG

Adds new constructor helpers

Merge pull request #3 from webfactory/add-constructor-helpers

Add more readable constructor methods