Update version requirements for psr/log

[itelmenko]

For an installing in Laravel 9:

Problem 1
- payprocessing/phpsdk 2.1.0 requires psr/log ^1.1 -> found psr/log[1.1.0, ..., 1.1.4] but the package is fixed to 3.0.0 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.
- payprocessing/phpsdk[2.1.1, ..., 2.1.2] require psr/log ^1.0 -> found psr/log[1.0.0, ..., 1.1.4] but the package is fixed to 3.0.0 (lock file version) by a partial update and that version does not match. Make sure you list it as an argument for the update command.
- Root composer.json requires payprocessing/phpsdk ^2.1 -> satisfiable by payprocessing/phpsdk[2.1.0, 2.1.1, 2.1.2].