Releases for Error Log

• Move CI to GitLabCI
• Bump phpstan to level 9 and add some additional type-checking logic

• #3335431: Add error log format configuration
• #3322359: README.txt with README.md

• Fix Drupal 10 compatibility.

Drupal 10 compatibility for development and testing purposes.

• Refactor logger class to simplify serialization support
• Fix static analysis issue

Resolve deprecations / test failures.

• #3084888: False positive error text on status page Remove unnecessary system status message - if you're not sure where PHP is logging, you could check PHP info.
• Fix some minor static analysis and code style issues.

Assorted minor fixes:

• #3059888: Implementations of LoggerInterface::log() should not return a value.
• Remove unnecessary severity from status report.
• Log levels should be a constant rather than method.

Initial release for Drupal 7.