Don't warn on on pre/post instrumentation task for testFixtures, possibly other sourceSets

[bric3]

Describe the bug
Instrumentation fails to ignore or recognize other source sets.

> Configure project :modules:core
[gradle-intellij-plugin :modules:corecore] Unexpected instrumentation task name: instrumentTestFixturesCode
[gradle-intellij-plugin :modules:corecore] Unexpected instrumentation task name: postInstrumentTestFixturesCode

To Reproduce
Steps to reproduce the behavior – provide your build configuration, and/or link to the failing GitHub Action job.

Adding the plugin id("java-test-fixtures"), will add a new source set testFixtures, gradle-intellij-plugin (as do other plugins) will react to this and create the above mentioned tasks.

Expected behavior
No warnings, I believe testFixtures are part of gradle and should be supported. That said is this really an issue if there are other source sets, like integrationTests, etc.

Environment:

• OS: macOS
• Gradle IntelliJ Plugin Version: 1.9.0
• Gradle Version: 7.5.1

[YannCebron]

#1081 sounds related