PHP 8.4 migration (#257)

* Explicitly mark all nullable parameters

This removes the deprecations introduced in PHP 8.4

* Make iterator return types match Iterator

PHP 8.4 makes not doing so a deprecation.

* Skip tesetErrorIsThrownAsException for PHP >= 8.4

PHP 8.4 deprecates the use of E_USER_ERROR. This can mangle the exception thrown. So, skip the test
in PHP 8.4. It may be possible to fix up what's being thrown, but I haven't found anything.

Since using trigger_error for user errors is now deprecated, error_to_exception() should probably be
deprecated as well. But that's a greater decision than making sure tests work correctly.

* Fix message matching in RepeatTest::testNegativeRepeatedtimes

PHP 8.4 has changed the format of __FUNCTION__ for closures, at least.

* Force doubles to ints in group()

PHP 8.4 deprecates the implicit conversion from doubles to ints when doing so would lose precision.
However, disallowing doubles as array keys in Functional would be a BC break.

* update CI matrix and actions

* use E_USER_DEPRECATED instead of E_USER_ERROR in test

* cs fixes

* update workflows

* add test for float keys

* update test workflow

* use the right method for phpunit < 9

* cs-fixer ignore env

* use the right method for phpunit < 9

* run pcov step only for php version 7.1 which uses older version of phpunit

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Co-authored-by: Michael D Johnson <mjohnson@pitsco.com>

Adding FUNDING file

Goodbye Travis and thank you @phanan

Merge pull request #235 from phanan-forks/fix-typo

fix: typo in match() deprecation message

Avoid double declaration of Functional\match (e.g. for preloading)

Prevent hash collisions for object hashing (#225)

Update build matrix (#219)

* Update build matrix

* Fix CS

Update `invoke_first` & `invoke_last` documentation. (#207)

* Update `invoke_first` & `invoke_last` documentation.

Closes #156.

* Fix coding style errors so build succeeds.

Add repeat() (#193)

Fix return type annotation on identical() (#179)