bump version to 5.0.0-rc4

Fix: Saving state isn't reset on error when editing sites (matomo-org…

…#21277)

updates expected UI test files

Prepare 4.15.2-b1

[automatic composer updates] (matomo-org#21154)

* updates composer dependencies

* updates expected test files

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Co-authored-by: sgiehl <sgiehl@users.noreply.github.com>
Co-authored-by: sgiehl <stefan@matomo.org>

prepare 4.15.1

prepare 5.0.0-b5

updates expected UI test files

updates all submodules (matomo-org#20977)

Co-authored-by: sgiehl <sgiehl@users.noreply.github.com>

Prepare 4.15.0-rc2