[BUG] Some slf4j warn message shows in the log file when sending email

[gaobinlong]

What is the bug?
When sending a email at the first time, OpenSearch main log shows that there are some slf4j related warn message, I think it should be eliminated:

[2023-06-26T17:02:40,596][WARN ][stderr                   ] [bcd07466ee01] SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
[2023-06-26T17:02:40,597][WARN ][stderr                   ] [bcd07466ee01] SLF4J: Defaulting to no-operation (NOP) logger implementation
[2023-06-26T17:02:40,597][WARN ][stderr                   ] [bcd07466ee01] SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.

How can one reproduce the bug?
Steps to reproduce the behavior:

1. Go to 'Alerting plugin of OSD '
2. Click on 'send test message' after you have setup email account correctly and creating a alerting monitor
3. See some warn log in OpenSearch main log file

What is the expected behavior?
Remove the unexpected warn log

What is your host/environment?

• OS: [MacOS]
• Version [3.0]
• Plugins: notification, alerting

Do you have any screenshots?

[Noir01]

Hi! I'll try my best to fix the bug.

[Hailong-am]

trying to reproduce in my local. when i try with slack webhook, there also have same waring message printed in console.

[Hailong-am]

@Noir01 @gaobinlong Add implementation "org.apache.logging.log4j:log4j-slf4j-impl:${versions.log4j}" to core/build.gradle dependencies will solve the issue