Upgrade phpunit, switch CI, PHP8 Fix

[baohx2000]

Upgraded phpunit, switch to github actions, fix for php 8. Take it or leave it.

I'll do another PR with just the php 8 fix.

[kelunik]

I forgot this exists and did the changes manually. -.-

https://github.com/amphp/injector/commit/d657e9d7a017ea498817c13f4f5cd4853cc21dee

[faizanakram99]

I forgot this exists and did the changes manually. -.-

amphp/injector@d657e9d

Is it a fork of this repository ? If so, why doesn't github show it as a fork ?

Also, what about this repository. Is this now unmaintained ?

In that case it would be better to archive this repository and used the one in amphp

[baohx2000]

It is a fork, but removed linkage is probably mainly due to namespace changes and default PHP version requirements without having done a major version bump. Hopefully someone can get a note and link into the readme on this repo. IIRC, there is an issue or comment somewhere here about moving to amphp.

[kelunik]

The API changed quite a lot, yeah, we'll add links once there's a new release.

[faizanakram99]

Ah ok, thanks

[kelunik]

Feedback on the new API is highly appreciated!

[Danack]

Thanks for the inspiration.....I eventually got around to upgrading things, but for reasons didn't accept the PR.

Probably going to be doing a 2.0 release 'soon'.