Remove PHP CS Fixer and PHPStan configs for now

.github/workflows/php-cs-fixer.yaml

@@ -1,18 +0,0 @@
-name: "Linter: PHP"
-
-on:
-  pull_request:
-    paths:
-      - '**.php'
-
-jobs:
-  php-cs-fixer:
-    runs-on: ubuntu-20.04
-
-    steps:
-      - uses: actions/checkout@v2
-
-      - name: PHP-CS-Fixer
-        uses: docker://oskarstark/php-cs-fixer-ga
-        with:
-          args: --dry-run

.github/workflows/phpstan.yaml

@@ -1,30 +0,0 @@
-name: Static analysis - PHPStan
-
-on:
-  pull_request:
-    paths:
-      - '**.php'
-
-jobs:
-  phpstan:
-    runs-on: ubuntu-20.04
-
-    steps:
-      - name: Setup PHP
-        uses: shivammathur/setup-php@v2
-        with:
-          php-version: '8.0'
-          extensions: "json,memcached"
-          ini-values: "memory_limit=-1"
-          coverage: none
-
-      - name: Checkout target branch
-        uses: actions/checkout@v2
-
-      - name: 'Install project dependencies'
-        run: |
-          composer update --no-interaction --prefer-dist --optimize-autoloader --prefer-stable
-
-      - name: phpstan
-        run: |
-          ./vendor/bin/phpstan --no-interaction --no-progress --level=0