Update to php8

[eldario]

Description

Changed

• Minimal require PHP version now is 8.0
• Package guzzlehttp/psr7 up to ^2.4
• Minimal phpstan/phpstan version now is 1.8
• Version of composer in docker container updated up to 2.5.3

Fixes #25 #20 #21 #22 #23

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I wrote unit tests for my code (if tests is required for my changes)
• I have made changes in CHANGELOG.md file

[codecov-commenter]

Codecov Report

Base: 100.00% // Head: 100.00% // No change to project coverage 👍

Coverage data is based on head (2939160) compared to base (c9d4c1a).
Patch coverage: 100.00% of modified lines in pull request are covered.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

Additional details and impacted files

@@             Coverage Diff             @@
##              master       #27   +/-   ##
===========================================
  Coverage     100.00%   100.00%           
  Complexity       123       123           
===========================================
  Files             23        23           
  Lines            386       405   +19     
===========================================
+ Hits             386       405   +19     

Flag	Coverage Δ
php	100.00% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
src/Frameworks/Laravel/ServiceProvider.php	100.00% <ø> (ø)
src/Requests/AbstractRequestBuilder.php	100.00% <100.00%> (ø)
...equests/Payments/PaymentsConfirmRequestBuilder.php	100.00% <100.00%> (ø)
src/Client.php	100.00% <0.00%> (ø)
src/Receipts/Receipt.php	100.00% <0.00%> (ø)
src/Requests/Traits/PaymentRequestTrait.php	100.00% <0.00%> (ø)
...c/Requests/Payments/PaymentsVoidRequestBuilder.php	100.00% <0.00%> (ø)
...equests/Payments/Cards/CardsAuthRequestBuilder.php	100.00% <0.00%> (ø)
...uests/Payments/Tokens/TokensAuthRequestBuilder.php	100.00% <0.00%> (ø)
... and 6 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.