Update copyright notices, upgrade nixos to 24.05, add php 8.4

Add coverage to nix matrix

Update readme, add changelog and package.xml

Update repository URL

Add get_pmu_event_info()

Attempt to further improve code coverage

Add an INI setting to control uint64_t -> zend_long overflow behavior

Test stubs and examples with phpstan and phpcs

Add some more "examples"

Add codecov.yml

Bump actions/checkout from 3 to 4

Display scaled values in phpinfo

Improve test coverage

Revert "Refactor out perf_event_open wrapper"

Refactor out perf_event_open wrapper