log level returned by getLevel function in custom logger not being respected.

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Reproducible in:

The Slack SDK version

"slack/bolt": "^3.13.0",

Node.js runtime version

v18.14.0

OS info

ProductName:            macOS
ProductVersion:         13.3
BuildVersion:           22E252
Darwin Kernel Version 22.4.0: Mon Mar  6 21:00:41 PST 2023; root:xnu-8796.101.5~3/RELEASE_ARM64_T8103

Steps to reproduce:

(Share the commands to run, source code, and project settings)

1. provide a logger to the new App() constructor
2. make logger getLevel method return info as the log level.

Expected result:

boltJS client should log at INFO level.

Actual result:

Logging at the DEBUG level.

[19:08:13.919] DEBUG (28297):
    0: "initialized"
[19:08:19.237] DEBUG (28297):
    0: "Initializing HTTPReceiver"
[19:08:19.237] DEBUG (28297):
    0: "The logLevel given to OAuth was ignored as you also gave logger"
[19:08:19.238] DEBUG (28297):
    0: "The logLevel given to WebClient was ignored as you also gave logger"
[19:08:19.238] DEBUG (28297):
    0: "initialized"

It seems like it's ignoring the value returned by getLevel(). I verified that the function is being called and is returning info by using breakpoints, and that it's calling my logger's debug function when logging the above messages. The The logLevel given to OAuth was ignored as you also gave logger are also somewhat confusing.

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Start by reproducing the custom-logger case through the new App constructor, with getLevel returning info, then trace the logger handling that invokes debug. Done means the configured info level is respected instead of producing DEBUG output; the payload does not name a source file or test to run.