lint container, workflows and composer update (#2591)

.github/workflows/linting.yaml

@@ -1,28 +0,0 @@
-name: Linting
-on:
-    pull_request: null
-    push:
-        branches:
-            - master
-jobs:
-    tests:
-        runs-on: ubuntu-latest
-        strategy:
-            matrix:
-                php: ['7.4', '8.0']
-
-        name: PHP ${{ matrix.php }}
-        steps:
-            -   uses: actions/checkout@v2
-            -   uses: shivammathur/setup-php@v2
-                with:
-                    php-version: ${{ matrix.php }}
-                    coverage: none
-                    extensions: mbstring, xml, ctype, iconv, intl, mysql, zip, gd, ldap
-                    tools: cs2pr:1.1.0
-            -   run: composer install --no-progress
-            -   run: composer validate --strict
-            -   run: vendor/bin/php-cs-fixer fix --dry-run --verbose --config=.php-cs-fixer.dist.php --using-cache=no --show-progress=none --format=checkstyle | cs2pr
-            -   run: vendor/bin/phpstan analyse src -c phpstan.neon --level=5 --no-progress --error-format=checkstyle | cs2pr
-            -   run: vendor/bin/phpstan analyse tests -c tests/phpstan.neon --level=5 --no-progress --error-format=checkstyle | cs2pr
-            -   run: composer kimai:code-lint