Semantic Logger returns Symbol for `#level`:
```
[1] pry(main)> SemanticLogger[Sidekiq].level
=> :debug
```
so current code fails with
```
[2] pry(main)> Sidekiq.logger = SemanticLogger[Sidekiq]
=> #<SemanticLogger::Logger:0x00007f1d27984a18 @filter=nil, @level=nil, @level_index=nil, @name="Sidekiq">
[3] pry(main)> Sidekiq.logger.debug?
ArgumentError: comparison of Symbol with 0 failed
from /home/ojab/.rbenv/versions/3.1.1/lib/ruby/gems/3.1.0/gems/sidekiq-6.4.1/lib/sidekiq/logger.rb:39:in
`<='
```
Calling `#{level}?` methods on the logger directly instead of
comparing `#level` with integer fixes that.
* logger_formatter -> log_format
* avoid touching global Sidekiq.logger in JobLogger
* rewrite tests for compactness and coverage
* hide banner in JSON
* Check Config File Existence (#4054)
* Check config file existence
* Eager config file check
* Parse expanded path to default sidekiq.yml config file in Rails app
* Cleanup
* Add minitest-around
* Extract context from formatter
* Add JSON logger formatter
* Adjust job logger to handle elapsed time within context
* Add tid test
* Rename processor logger
* Enforce global state reset in logging tests
* Add warning about upcoming refactoring to Sidekiq::Logging
* Replace around hook with explicit stub inside test
It's implemented with fibers, which means Thread.current returns different values in JRuby.
* Fix typo
* Concise JSON formatter keys
* Add logger_formatter option
* Shift context from array of strings to hash
Allows more flexibly format context in the different formatters.
* Adjust warning message regarding context type change
* Add "Formatter" suffix to classes
* Fix CLI specs
* Replace Sidekiq::Logging with Sidekiq::Logger
* Namespace logger formatters
* Remove rails 4 appraisal
