Add PHP 8.0 on GitHub action and Fix Psalm issue

Author: peter279k

.github/workflows/coding-standards.yml

@@ -20,6 +20,7 @@ jobs:
           - "locked"
         php-version:
           - "7.4"
+          - "8.0"
         operating-system:
           - "ubuntu-latest"
 

.github/workflows/mutation-tests.yml

@@ -20,6 +20,7 @@ jobs:
           - "locked"
         php-version:
           - "7.4"
+          - "8.0"
         operating-system:
           - "ubuntu-latest"
 
@@ -60,4 +61,4 @@ jobs:
         env:
           INFECTION_BADGE_API_KEY: ${{ secrets.INFECTION_BADGE_API_KEY }}
           STRYKER_DASHBOARD_API_KEY: ${{ secrets.STRYKER_DASHBOARD_API_KEY }}
-  
+

.github/workflows/phpunit.yml

@@ -20,6 +20,7 @@ jobs:
           - "locked"
         php-version:
           - "7.4"
+          - "8.0"
         operating-system:
           - "ubuntu-latest"
 

.github/workflows/psalm.yml

@@ -20,6 +20,7 @@ jobs:
           - "locked"
         php-version:
           - "7.4"
+          - "8.0"
         operating-system:
           - "ubuntu-latest"
 

src/MiddlewarePipeline.php

@@ -53,7 +53,6 @@ function (ServerRequestInterface $request) {
                 /** @var string $requestId */
                 $requestId = $request->getAttribute('request_id');
                 try {
-                    /** @var MiddlewareInterface $middleware */
                     $middleware = $this->concurrentPipelines[$requestId]->dequeue();
 
                     $response = $middleware->process($request, $this);
@@ -84,7 +83,6 @@ public function process(ServerRequestInterface $request, RequestHandlerInterface
                 /** @var string $requestId */
                 $requestId = $request->getAttribute('request_id');
                 try {
-                    /** @var MiddlewareQueue $queue */
                     $queue = $this->concurrentPipelines[$requestId];
                     $next = new NextHandler($queue, $handler);