stubNoWarnIfNotFound does not hide "Type not found" warnings

[roded]

Using the gradle plugin, even when -AstubNoWarnIfNotFound=true has been provided, checkerframework still warns about missing stub types:

> Task :compileJava
warning: /home/roded/dev/games/checkerframework-stubNoWarnIfNotFound/checkerframework/kr.pe.kwonnam.slf4jlambda.LambdaLogger.astub:(line 5,col 1): Type not found: kr.pe.kwonnam.slf4jlambda.LambdaLogger
1 warning

I'll soon attach a reproduction project.

Edit: A project reproducing the issue can be found here:
https://github.com/roded/checker-framework-issue-5390

Clone and run ./gradlew build:

[roded@ryzen checker-framework-issue-5390]$ ./gradlew build

Welcome to Gradle 7.4!

Here are the highlights of this release:
 - Aggregated test and JaCoCo reports
 - Marking additional test source directories as tests in IntelliJ
 - Support for Adoptium JDKs in Java toolchains

For more details see https://docs.gradle.org/7.4/release-notes.html

Starting a Gradle Daemon, 2 stopped Daemons could not be reused, use --status for details

> Task :compileJava
warning: /home/roded/dev/games/checker-framework-issue-5390/checkerframework/kr.pe.kwonnam.slf4jlambda.LambdaLogger.astub:(line 5,col 1): Type not found: kr.pe.kwonnam.slf4jlambda.LambdaLogger
1 warning

BUILD SUCCESSFUL in 8s
3 actionable tasks: 3 executed