Do not build with lowest PHPStan version

Author: ondrejmirtes

.github/workflows/build.yml

@@ -128,9 +128,6 @@ jobs:
           - "7.3"
           - "7.4"
           - "8.0"
-        dependencies:
-          - "lowest"
-          - "highest"
 
     steps:
       - name: "Checkout"
@@ -144,12 +141,7 @@ jobs:
           extensions: mbstring
           tools: composer:v2
 
-      - name: "Install lowest dependencies"
-        if: ${{ matrix.dependencies == 'lowest' }}
-        run: "composer update --prefer-lowest --no-interaction --no-progress --no-suggest"
-
-      - name: "Install highest dependencies"
-        if: ${{ matrix.dependencies == 'highest' }}
+      - name: "Install dependencies"
         run: "composer update --no-interaction --no-progress --no-suggest"
 
       - name: "Update PHPUnit"