Allow latest `psr/*` dependencies

[geerteltink]

This PR allow latest psr dependencies.

[geerteltink]

@lcobucci do you have an idea why this is failing for php 8.0 with lowest dependencies only?

1) MezzioTest\Authentication\OAuth2\Pdo\OAuth2PdoMiddlewareTest::testProcessClientCredentialGrantConfidential
Lcobucci\JWT\Signer\InvalidKeyProvided: It was not possible to parse your key, reason: error:0909006C:PEM routines:get_name:no start line

[lcobucci]

@lcobucci do you have an idea why this is failing for php 8.0 with lowest dependencies only?

1) MezzioTest\Authentication\OAuth2\Pdo\OAuth2PdoMiddlewareTest::testProcessClientCredentialGrantConfidential
Lcobucci\JWT\Signer\InvalidKeyProvided: It was not possible to parse your key, reason: error:0909006C:PEM routines:get_name:no start line

I'll have a look. OpenSSL usually gives that error when the key is empty or something like that.

I also see that composer is installing v3.4.6 when running PHP 8.0, which shouldn't be possible as it isn't compatible with that version: https://packagist.org/packages/lcobucci/jwt#3.4.6

[geerteltink]

Interesting:

Received job: {"command":"./vendor/bin/phpunit","php":"8.0","extensions":["pdo-sqlite"],"ini":["memory_limit        = -1"],"dependencies":"lowest","ignore_platform_reqs_8":true,"ignore_php_platform_requirement":true,"additional_composer_arguments":[]}

Where is that config coming from?

[Ocramius]

@froschdesign do we need to fix markdownlint before merging here? Seems like it wasn't run at all before :thinking:

[geerteltink]

@Ocramius It has to be fixed anyway. I'll try to do it today.