Simple run of composer update. Will check somewhen later if there are any packages where we should consider updating to a new major version maybe.

• Upgrading composer/ca-bundle (1.2.8 => 1.2.10)
• Upgrading davaxi/sparkline (1.2.2 => 1.2.3)
• Upgrading dealerdirect/phpcodesniffer-composer-installer (v0.7.0 => v0.7.1)
• Upgrading escapestudios/symfony2-coding-standard (3.11.0 => 3.12.0)
• Upgrading matomo/matomo-php-tracker (3.0.0 => 3.0.1)
• Upgrading matomo/searchengine-and-social-list (3.11.0 => 3.12.0)
• Upgrading maxmind-db/reader (v1.8.0 => v1.10.1)
• Upgrading monolog/monolog (1.25.5 => 1.26.1)
• Upgrading opis/closure (3.6.1 => 3.6.2)
• Upgrading pear/archive_tar (1.4.13 => 1.4.14)
• Upgrading pear/pear_exception (v1.0.1 => v1.0.2)
• Upgrading phar-io/manifest (1.0.3 => 2.0.3)
• Upgrading phar-io/version (2.0.1 => 3.1.0)
• Upgrading php-di/php-di (6.3.0 => 6.3.4)
• Upgrading phpspec/prophecy (1.12.1 => 1.13.0)
• Upgrading phpunit/php-code-coverage (7.0.10 => 7.0.15)
• Upgrading phpunit/php-file-iterator (2.0.2 => 2.0.4)
• Upgrading phpunit/php-timer (2.1.2 => 2.1.3)
• Upgrading phpunit/php-token-stream (3.1.1 => 3.1.3)
• Upgrading phpunit/phpunit (8.5.9 => 8.5.18)
• Upgrading psr/container (1.0.0 => 1.1.1)
• Upgrading psr/log (1.1.3 => 1.1.4)
• Upgrading sebastian/code-unit-reverse-lookup (1.0.1 => 1.0.2)
• Upgrading sebastian/comparator (3.0.2 => 3.0.3)
• Upgrading sebastian/diff (3.0.2 => 3.0.3)
• Upgrading sebastian/environment (4.2.3 => 4.2.4)
• Upgrading sebastian/exporter (3.1.2 => 3.1.3)
• Upgrading sebastian/global-state (3.0.0 => 3.0.1)
• Upgrading sebastian/object-enumerator (3.0.3 => 3.0.4)
• Upgrading sebastian/object-reflector (1.1.1 => 1.1.2)
• Upgrading sebastian/recursion-context (3.0.0 => 3.0.1)
• Upgrading sebastian/resource-operations (2.0.1 => 2.0.2)
• Upgrading sebastian/type (1.1.3 => 1.1.4)
• Upgrading squizlabs/php_codesniffer (3.5.8 => 3.6.0)
• Upgrading symfony/polyfill-ctype (v1.20.0 => v1.23.0)
• Upgrading symfony/polyfill-iconv (v1.20.0 => v1.23.0)
• Upgrading symfony/polyfill-mbstring (v1.20.0 => v1.23.0)
• Upgrading tecnickcom/tcpdf (6.4.1 => 6.4.2)
• Upgrading theseer/tokenizer (1.2.0 => 1.2.1)
• Upgrading twig/twig (v3.1.1 => v3.3.2)
• Upgrading webmozart/assert (1.9.1 => 1.10.0)

Note: The failing tests regarding missing search engine icons should be fixed again with #17811